Subject: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Microsoft Investigates Windows 11 25H2 Boot Failures After January Update <https://cyberpress.org/microsoft-investigates-windows-11-25h2/>

Microsoft has launched an urgent investigation into severe stability
issues plaguing the January 2026 security update for Windows 11 after
the patch triggered critical boot failures on physical devices.

The update, identified as KB5074109, was intended to deliver security enhancements to Windows 11 versions 25H2 and 24H2 but instead caused widespread ?UNMOUNTABLE_BOOT_VOLUME? errors that render affected systems unusable.

... more ....


Related:

[HK01]Win 11???????????????????????????
???:
<https://www.hk01.com/%E6%95%B8%E7%A2%BC%E7%94%9F%E6%B4%BB/60316988/>



--
@~@ Simplicity is Beauty! Remain silent! Drink, Blink, Stretch!
/ v \ May the Force and farces be with you! Live long and prosper!!
/( _ )\ https://sites.google.com/site/changmw/
^ ^ https://github.com/changmw/changmw


--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

"Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

https://www.hk01.com/%E6%95%B8%E7%A2%BC%E7%94%9F%E6%B4%BB/60316988/

(Had to use Google Translate. If there is a languages button, they
didn't use the alternate language as text on the button.)

"Your device has encountered a problem and needs to restart. You can
restart." At this point, the device cannot complete the boot process
and requires manual recovery steps.

Microsoft did not provide specific steps.

Wonder what are the manual recovery steps? Restore using an image
backup, maybe? And then disable or postpone any further updates for
months? You know, those scheduled (not manual) image backups that users
are supposed to do, but most don't.

The only solution is to enter the Windows recovery environment and
uninstall the latest security patches.

Presumes you can get that far in a bootup. We're supposed to permit
Secure Boot, TPM, and Memory Integrity as protections against hackers,
but the most likely source of attack is Microsoft.

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Wed, 1/28/2026 10:37 AM, VanguardLH wrote:

"Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

https://www.hk01.com/%E6%95%B8%E7%A2%BC%E7%94%9F%E6%B4%BB/60316988/

(Had to use Google Translate. If there is a languages button, they
didn't use the alternate language as text on the button.)

"Your device has encountered a problem and needs to restart. You can
restart." At this point, the device cannot complete the boot process
and requires manual recovery steps.

Microsoft did not provide specific steps.

Wonder what are the manual recovery steps? Restore using an image
backup, maybe? And then disable or postpone any further updates for
months? You know, those scheduled (not manual) image backups that users
are supposed to do, but most don't.

The only solution is to enter the Windows recovery environment and
uninstall the latest security patches.

Presumes you can get that far in a bootup. We're supposed to permit
Secure Boot, TPM, and Memory Integrity as protections against hackers,
but the most likely source of attack is Microsoft.

But look at the evidence though.

Normally, the stop code would be "Inaccessible Boot Volume".
And it has a numeric value, like 0x7b or so. Something like that.

Notice in the screenshots of this one, there is no numeric
stop code, and the message is more of a

"Cannot mount Boot Volume" # That means the volume seems trashed
^^^^^ # as if it is a BitLocker failure

which is not the same thing.

To me, the Cannot mount Boot Volume means the volume was
encrypted, and the attempt to unlock it has failed.

If you had this failure, you would be researching the info
on BitLocker recoveries.

*******

Yesterday, I installed Windows 11 Pro in QEMU-KVM on Linux, as
a virtual machine. I used ByPassNRO on it, so there was no MSA
associated with the install. I installed using 24H2, with the
network cable disconnected.

What did it do ? I caught it in the process of encrypting C: :-/

I wonder when they were planning on giving me the recovery key ???

The virtual machine in that case, has "swtpm" from IBM, so the
key information could be installed in the TPM.

Note that, Microsoft is <cough> preparing to attack UEFI
and add the 2023 certificate and remove the 2011 certificate.
If it removes the 2011 certificate, it's always possible
your old copy of Windows 10 would not boot. Also, the signing
shim on your Linux Dual Boot (secure boot) depends on the
certificate, and that could be busted too (but this is only if
you are using Secure Boot or Secure Boot is the only option
on your shiny-new year-2026 computer).

At the very least then, as part of defensive computing, you should
keep a FAT USB key handy, and enter the BIOS screen where the MOK
is stored. There is an option there to back up UEFI materials.
The BIOS will write out to a FAT filesystem.
In an emergency, your backup of the content may be brought
into play, if something seems broken beyond repair.

That doesn't back up the TPM. A TPM that could be physical,
or a TPM that is emulated as BIOS code (and uses a secure enclave
on the CPU).

Paul

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Wed, 28 Jan 2026 21:28:42 +0800, "Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

I have, over the past 3-4 months, been seeing weird Chrome stuff
("can't find chrome" in a search that somehow began overnight, when
the system is running to do auto-updates, etc--but nobody using system
to so a search or anything else).

System runs 24/7 on UPS, Win11, 25H2 seems to be running fine, and so
on. No other computers connected to a network (straight out via
Comcast gateway to Internet) and my own domain--used for e-mail
forwarding. All current patches/updates installed.

Anyone else seeing something similar with "chrome" search not found?

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Paul <nospam@needed.invalid> wrote:

VanguardLH wrote:

"Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

https://www.hk01.com/%E6%95%B8%E7%A2%BC%E7%94%9F%E6%B4%BB/60316988/

(Had to use Google Translate. If there is a languages button, they
didn't use the alternate language as text on the button.)

"Your device has encountered a problem and needs to restart. You can
restart." At this point, the device cannot complete the boot process
and requires manual recovery steps.

Microsoft did not provide specific steps.

Wonder what are the manual recovery steps? Restore using an image
backup, maybe? And then disable or postpone any further updates for
months? You know, those scheduled (not manual) image backups that users
are supposed to do, but most don't.

The only solution is to enter the Windows recovery environment and
uninstall the latest security patches.

Presumes you can get that far in a bootup. We're supposed to permit
Secure Boot, TPM, and Memory Integrity as protections against hackers,
but the most likely source of attack is Microsoft.

But look at the evidence though.

Normally, the stop code would be "Inaccessible Boot Volume".
And it has a numeric value, like 0x7b or so. Something like that.

Notice in the screenshots of this one, there is no numeric
stop code, and the message is more of a

"Cannot mount Boot Volume" # That means the volume seems trashed
^^^^^ # as if it is a BitLocker failure

which is not the same thing.

To me, the Cannot mount Boot Volume means the volume was
encrypted, and the attempt to unlock it has failed.

If you had this failure, you would be researching the info
on BitLocker recoveries.

*******

Yesterday, I installed Windows 11 Pro in QEMU-KVM on Linux, as
a virtual machine. I used ByPassNRO on it, so there was no MSA
associated with the install. I installed using 24H2, with the
network cable disconnected.

What did it do ? I caught it in the process of encrypting C: :-/

I wonder when they were planning on giving me the recovery key ???

The virtual machine in that case, has "swtpm" from IBM, so the
key information could be installed in the TPM.

Note that, Microsoft is <cough> preparing to attack UEFI
and add the 2023 certificate and remove the 2011 certificate.
If it removes the 2011 certificate, it's always possible
your old copy of Windows 10 would not boot. Also, the signing
shim on your Linux Dual Boot (secure boot) depends on the
certificate, and that could be busted too (but this is only if
you are using Secure Boot or Secure Boot is the only option
on your shiny-new year-2026 computer).

At the very least then, as part of defensive computing, you should
keep a FAT USB key handy, and enter the BIOS screen where the MOK
is stored. There is an option there to back up UEFI materials.
The BIOS will write out to a FAT filesystem.
In an emergency, your backup of the content may be brought
into play, if something seems broken beyond repair.

That doesn't back up the TPM. A TPM that could be physical,
or a TPM that is emulated as BIOS code (and uses a secure enclave
on the CPU).

With a trial of Win11 Pro inside a Virtualbox VM, I used Rufus to create
a modified ISO where: MSA was disabled, Secure Boot was not required,
TPM was not required, and Bitlocker was blocked. I'm not using
Bitlocker in Win10. In fact, in prep for Win10 to Win11, I did the
following registry edits:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BitLocker
Data item: PreventDeviceEncryption (DWORD)
Data value: 1 (enable the disable)

I don't need to protect the programs as anyone could get those from
their sources. I don't need to protect MS Windows, Office, CCleaner, or
any software from theft. As for my own sensitive data, I've been using TrueCrypt (now Veracrypt) for years to mount encrypted containers. I
don't need nor want whole-disk encryption. I don't need nor want to
encrypt programs. Only some (not all) of my data files need encryption.

I haven't yet rebooted just to check the BIOS screens to where is the
MOK you mentioned (Machine Owner Key perhaps?). Alas, while the Asrock
mobo manual mentions the Secure Boot setting in BIOS, it doesn't show
the screen displayed after selecting that option. Maybe when I select
the Secure Boot option, the next screen lets me export the certs/keys.

I'll have to format a USB drive using FAT32 to be prepared for whatever
I find available under the Secure Boot settings when I reboot to enter
BIOS.

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Wed, 1/28/2026 2:22 PM, jerryab wrote:

On Wed, 28 Jan 2026 21:28:42 +0800, "Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

I have, over the past 3-4 months, been seeing weird Chrome stuff
("can't find chrome" in a search that somehow began overnight, when
the system is running to do auto-updates, etc--but nobody using system
to so a search or anything else).

System runs 24/7 on UPS, Win11, 25H2 seems to be running fine, and so
on. No other computers connected to a network (straight out via
Comcast gateway to Internet) and my own domain--used for e-mail
forwarding. All current patches/updates installed.

Anyone else seeing something similar with "chrome" search not found?

Are you relying on MSFT SearchIndexer for your indexing ?

We use Agent Ransack (MythicSoftware) or Everything.exe (voidtools.com)
for search. Everything.exe is an Indexer too, except it only keeps
filenames. The Microsoft SearchIndexer, indexes content (like your .eml files) and indexes filenames.

In the Explorer search box

filename:"*chrome*"

might select for the filename in question. The asterisks
for wildcarding help match on strings where that is a substring.

By default, Program Files is not indexed.

There are other keywords for selecting various aspects of an Explorer search.

content:"doppelganger" filename:"*jackbenimble*" ext:txt

But for *reliable* search you can brute force the machine using
Agent Ransack.

The next level of investigation (when materials are hidden behind
"access denied") is to use "nfi.exe" utility from Microsoft.
It reads the $MFT and it does not stat() anything. When a program
attempts to stat() something, it can get "access denied" and
then it may not list the file at all! That's what Everything.exe
does when it hits trouble. For example, when Microsoft WSL1 stored
the raw files of a foreign OS in a tree, Everything.exe would
not list any file in that tree. Whereas nfi.exe would have
no trouble at all.

The "nfi.exe" is inside this ZIP file.

https://web.archive.org/web/20150329185738/http://download.microsoft.com/download/win2000srv/utility/3.0/nt45/en-us/oem3sr2.zip

(administrator command prompt)

cd /d %userprofile%\Downloads # Example usage
nfi.exe c: > nfi-c-out.txt
notepad nfi-c-out.txt

No utility on Windows lists all the files. Our job is to make
sure when one utility lists 300,000 files and another utility
lists 400,000 files, that we're using both lists and finding
any unique additions.

In the $MFT, I did find a couple entries near the end of the
$MFT that did not have filename strings. My parser was failing
there. The nfi.exe does not fail on those, it just ignores them
(because the entries fail at the parsing stage). They're suggestive
of some sort of extension mechanism, but what that is, I can't even
guess.

Summary: Have we seen the Microsoft search (explorer.exe) fail ?
Of course!

And it doesn't have to be the word "chrome" either.
I am constantly robbed of hits.

You can dump the contents of Windows.db but that's
sufficient material for another post. Now, try and find
"Windows.db". Aha! Hidden it is.
Unless you use a third party utility.

C:\ProgramData\Microsoft\Search\Data\Applications\Windows
Windows.db 2,056,192 bytes [ can be ~4GB if fully populated ]
$ file Windows.db
Windows.db: SQLite 3.x database, last written using SQLite version 3046000

Use "sqlitebrowser" on Linux for a look. The inverted content index table,
you can ignore that. But a couple filename related tables identify what has been Indexed
by the MSFT SearchIndexer.exe . The "numbers" are filenum (as seen in nfi.exe).

Using Indexing Options you can "make" the explorer search, search everything.
[ control.exe Indexing Options control panel ]
But it is not easy programming that. Give it a try. See if you can (eventually)
make your Windows.db ~4GB in size...

Paul

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On 1/28/2026 6:28 AM, Mr. Man-wai Chang wrote:

Microsoft Investigates Windows 11 25H2 Boot Failures After January Update <https://cyberpress.org/microsoft-investigates-windows-11-25h2/>

Microsoft has launched an urgent investigation into severe stability
issues plaguing the January 2026 security update for Windows 11 after
the patch triggered critical boot failures on physical devices.

The update, identified as KB5074109, was intended to deliver security enhancements to Windows 11 versions 25H2 and 24H2 but instead caused widespread ?UNMOUNTABLE_BOOT_VOLUME? errors that render affected systems unusable.

Compliments of the Patch Lady, Susan B. Manager of AskWoody <https://www.askwoody.com/forums/topic/ms-defcon-3-i-wish-we-had-a-level-2-5/#post-2840717>
=> Note: Current analysis indicates problem is occurring/reported on commercial use devices, not home-use or nor on virtual machines..


Microsoft is investigating a limited number of reports of an issue in
which devices are failing to boot with stop?code,
?UNMOUNTABLE_BOOT_VOLUME?, after installing the January 2026 Windows
security update (KB5074109), released January 13, 2026, and later
updates. Affected devices show a black screen with the message ?Your
device ran into a problem and needs a restart. You can restart.? At this stage, the device cannot complete startup and requires manual recovery
steps. Reports received so far indicate that this issue is limited to commercial physical devices; no customers have reported observing these symptoms on home use devices, nor on virtual machines.
Recent investigations have determined this issue can occur on devices
that failed to install the December 2025 security update and were left
in an improper state after rolling back the update. Attempting to
install Windows updates while in this improper state could result in the device being unable to boot. We are working on a partial resolution that
will prevent additional devices from resulting in a no-boot scenario if
they try to install an update while in this improper state. However,
this partial resolution will not prevent devices from getting into the improper state in the first place, nor will it repair devices that are
already unable to boot. We continue to investigate why these devices are failing to install Windows updates or potentially getting into this
improper state.
If you?are?experiencing?this issue,?please?contact?Support for business [link]?or?use Feedback Hub to file a report.?For additional information, see?Send feedback to Microsoft with the Feedback Hub app [link]. Next steps:?We are working to release a partial resolution in a future update
and continue to investigate the cause of this issue. We will provide
more information when it is available.
</qp>

Also see Lawrence Abrams BleepingComputer article/post <https://www.bleepingcomputer.com/news/microsoft/microsoft-links-windows-11-boot-failures-to-failed-december-2025-update/>


--
...w­¤?ñ?¤

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On 1/28/2026 8:37 AM, VanguardLH wrote:

"Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

https://www.hk01.com/%E6%95%B8%E7%A2%BC%E7%94%9F%E6%B4%BB/60316988/

(Had to use Google Translate. If there is a languages button, they
didn't use the alternate language as text on the button.)

"Your device has encountered a problem and needs to restart. You can
restart." At this point, the device cannot complete the boot process
and requires manual recovery steps.

Microsoft did not provide specific steps.

Wonder what are the manual recovery steps? Restore using an image
backup, maybe? And then disable or postpone any further updates for
months? You know, those scheduled (not manual) image backups that users
are supposed to do, but most don't.

The only solution is to enter the Windows recovery environment and
uninstall the latest security patches.

Presumes you can get that far in a bootup. We're supposed to permit
Secure Boot, TPM, and Memory Integrity as protections against hackers,
but the most likely source of attack is Microsoft.

Issue atm appears limited to commercial use devices.
..and only if the Dec. update failed to install, rolling back the device
to pre-Dec update but leaving the device in a condition that causes the
Jan. update to cause the problem.

i.e. If home user or vm and the Dec. update was installed(without fail),
it is unlikely you will be impacted nor need a recovery method.
...but based on the current information, recovery, if impacted, would
entail the usual route.
- restore to pre-dec condition (update again with Jan update)
- restore to pre-dec condtions (update again with Dec and Jan update)
- clean install
- install on top


--
...w­¤?ñ?¤

--- PyGate Linux v1.5.6
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Thu, 1/29/2026 12:27 AM, Paul wrote:

On Wed, 1/28/2026 2:22 PM, jerryab wrote:

On Wed, 28 Jan 2026 21:28:42 +0800, "Mr. Man-wai Chang"
<toylet.toylet@gmail.com> wrote:

I have, over the past 3-4 months, been seeing weird Chrome stuff
("can't find chrome" in a search that somehow began overnight, when
the system is running to do auto-updates, etc--but nobody using system
to so a search or anything else).

System runs 24/7 on UPS, Win11, 25H2 seems to be running fine, and so
on. No other computers connected to a network (straight out via
Comcast gateway to Internet) and my own domain--used for e-mail
forwarding. All current patches/updates installed.

Anyone else seeing something similar with "chrome" search not found?

[Picture] You can use "Download Original" for full resolution

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif

When you modify the settings in the Indexing Options,
then more of the C: partition can be indexed for you.

I indexed my latest install, and the Windows.db was ~1.4GB.
And that took hours to generate.

Paul


--- PyGate Linux v1.5.8
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Paul wrote:

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably
for a user account. I had a similar one there but when hovered over with
the mouse, said "this [something] is no longer available" or similar. I
didn't take much notice and can't recall the exact wording. I just
unchecked it and it disappeared, never to return. I'm wondering what it
was for.

I indexed my latest install, and the Windows.db was ~1.4GB.
And that took hours to generate.

Mine's about 23MB but doesn't include the whole drive.

--- PyGate Linux v1.5.8
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Sat, 1/31/2026 6:10 AM, Apd wrote:

Paul wrote:

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably
for a user account. I had a similar one there but when hovered over with
the mouse, said "this [something] is no longer available" or similar. I didn't take much notice and can't recall the exact wording. I just
unchecked it and it disappeared, never to return. I'm wondering what it
was for.

I indexed my latest install, and the Windows.db was ~1.4GB.
And that took hours to generate.

Mine's about 23MB but doesn't include the whole drive.

CSC is apparently "Client Side Caching", whatever that means.

Paul


--- PyGate Linux v1.5.8
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Paul wrote:

On Sat, 1/31/2026 6:10 AM, Apd wrote:

Paul wrote:

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif >>

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably
for a user account.

[...]

CSC is apparently "Client Side Caching", whatever that means.

That sounds like a reasonable interpretation. Presenting what appears to
be an internal implementation detail to the user is a bad idea (or a
bug)!

--- PyGate Linux v1.5.10
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

On Sun, 2/1/2026 5:11 AM, Apd wrote:

Paul wrote:

On Sat, 1/31/2026 6:10 AM, Apd wrote:

Paul wrote:

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably >>> for a user account.

[...]

CSC is apparently "Client Side Caching", whatever that means.

That sounds like a reasonable interpretation. Presenting what appears to
be an internal implementation detail to the user is a bad idea (or a
bug)!

If you asked me where that was, I doubt I could find it.

Googling, says it is here.

C:\Windows\CSC

I can see it in an NFI output from Windows 10.

File 101681
\Windows\CSC\v2.0.6\NAMESP~1 [probably NAMESPACE]

There don't seem to be any files in there.

Paul

--- PyGate Linux v1.5.10
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Paul wrote on 2/1/2026 6:42 AM:

On Sun, 2/1/2026 5:11 AM, Apd wrote:

Paul wrote:

On Sat, 1/31/2026 6:10 AM, Apd wrote:

Paul wrote:

https://i.postimg.cc/ht059W0z/Indexing-Options-Modify-For-Thoroughness.gif

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably >>>> for a user account.

[...]

CSC is apparently "Client Side Caching", whatever that means.

That sounds like a reasonable interpretation. Presenting what appears to
be an internal implementation detail to the user is a bad idea (or a
bug)!

If you asked me where that was, I doubt I could find it.

Googling, says it is here.

C:\Windows\CSC

I can see it in an NFI output from Windows 10.

File 101681
\Windows\CSC\v2.0.6\NAMESP~1 [probably NAMESPACE]

There don't seem to be any files in there.

Paul

- folder is normally empty
- Hidden(by default)
Content(if present) can be viewed after enabling 'Hidden operating
system files' - may have to take ownership of folder.
- Intended to work when Offline files is enabled(Control Panel/Sync Center/Manage offline files)

Afiak, its included in Win11, possibly for backward compatibility or
user preference for local storage instead of OneDrive or other storage.
- could eventually be deprecated (limited use in the enterprise arena)


--
...w­¤?ñ?¤

--- PyGate Linux v1.5.10
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

Subject: Re: Microsoft Investigates Windows 11 25H2 Boot Failures After January Update

Paul wrote:

On Sun, 2/1/2026 5:11 AM, Apd wrote:

Paul wrote:

On Sat, 1/31/2026 6:10 AM, Apd wrote:

csc://{S-1-5-21- ... -1001}

That's some weird URI with an unknown scheme (csc) and a SID, presumably >>>> for a user account.

[...]

CSC is apparently "Client Side Caching", whatever that means.

That sounds like a reasonable interpretation. Presenting what appears to
be an internal implementation detail to the user is a bad idea (or a
bug)!

If you asked me where that was, I doubt I could find it.

Googling, says it is here.

C:\Windows\CSC

Apparently it's the cache for offline (network) files which is disabled
here. I can see it in Explorer but couldn't read or get in so took admin ownership (it belonged to system) and set permissions. I don't know why
the indexer would want to include such a directory that can't normally
be accessed, especially labelling it or its content with an
incomprehensible URI.

I can see it in an NFI output from Windows 10.

File 101681
\Windows\CSC\v2.0.6\NAMESP~1 [probably NAMESPACE]

There don't seem to be any files in there.

Just two files (pq, sm) of a few bytes, empty namespace and temp
directories in mine. Thanks for helping to clear this up.

--- PyGate Linux v1.5.10
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)