KB5066794: Servicing stack update for Windows Server 2012 R2: October 14, 2025

Applies To
Windows Server 2012 R2 ESU

Note

  • Windows Secure Boot certificate expiration
  • Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Microsoft has been updating these certificates on consumer and non-managed business devices for the past months. Devices that haven’t received the newer certificates will continue to start and operate normally, and standard Windows updates will continue to install. We will continue to install the newer certificates via Windows updates in the coming months.
  • You can check your PC status on the Windows Security app. If you are an IT administrator, follow the guidance on the Secure Boot Playbook for Windows clients and Windows Server.
End of support information

Note

  • Support for Windows Server 2012 R2 will end in October 2026
  • Windows Server 2012 R2 reached the end of support (EOS) on October 10, 2023.
  • Extended Security Updates (ESUs) are available for purchase and will continue for three years, renewable on an annual basis, until the final date on October 13, 2026. For information about the procedure to continue receiving security updates, see KB5031043.
  • We recommend that you upgrade to a later version of Windows Server. For more information, see Overview of Windows Server upgrades.

Summary

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) makes sure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Important Not installing the latest SSU before applying Windows updates might result in the Windows update not being offered until the latest SSU is installed.

How to get this update

Install this update

To install this update, use one of the following release channels.


Available Next step
Available This update is available through Windows Update. It will be downloaded and installed automatically.
Prerequisites There are no prerequisites to apply this update.
Restart information You do not have to restart your computer after you apply this update.
Removal information Servicing stack updates (SSUs) make changes to how updates are installed and cannot be uninstalled from the device.
Update replacement information This update replaces the previously released update KB5065767.

File Information

The English (United States) version of this software update installs files that have the following attributes. This update might contain files for additional languages.

For all supported x64-based verions
File name File version Date Time File size
httpai.dll 6.3.9600.22819 12-Sep-25 22:33 57,856
peerdistai.dll 6.3.9600.22819 12-Sep-25 22:33 72,192
PrintAdvancedInstaller.dll 6.3.9600.22819 12-Sep-25 22:48 102,400
msdtcadvancedinstaller.dll 6.3.9600.22819 12-Sep-25 22:33 257,536
netfxconfig.dll 6.3.9600.22819 12-Sep-25 23:03 34,816
ConfigureIEOptionalComponentsAI.dll 6.3.9600.22819 12-Sep-25 22:33 84,992
IEFileInstallAI.dll 6.3.9600.22819 12-Sep-25 22:29 68,096
servicemodelregai.dll 6.3.9600.22819 12-Sep-25 22:33 115,200
SetIEInstalledDateAI.dll 6.3.9600.22819 12-Sep-25 22:33 51,712
ceipfwdai.dll 6.3.9600.22819 12-Sep-25 22:30 228,352
bcdeditai.dll 6.3.9600.22819 12-Sep-25 22:35 287,232
appxreg.dll 6.3.9600.22819 12-Sep-25 22:56 14,848
RegisterIEPKeysAI.dll 6.3.9600.22819 12-Sep-25 22:31 19,968
cmipnpinstall.dll 6.3.9600.22819 12-Sep-25 23:01 248,832
appserverai.dll 6.3.9600.22819 12-Sep-25 23:00 146,432
RDWebAI.dll 6.3.9600.22819 12-Sep-25 22:44 140,800
tssdisai.dll 6.3.9600.22819 12-Sep-25 22:42 156,160
VmHostAI.dll 6.3.9600.22819 12-Sep-25 22:48 123,392
securebootai.dll 6.3.9600.22819 12-Sep-25 22:34 194,048
winsockai.dll 6.3.9600.22819 12-Sep-25 22:33 69,632
ws2_helper.dll 6.3.9600.22819 12-Sep-25 22:34 62,976
cleanupai.dll 6.3.9600.22819 12-Sep-25 22:33 33,792
wdscore.dll 6.3.9600.22819 12-Sep-25 22:34 276,480
CntrtextInstaller.dll 6.3.9600.22819 12-Sep-25 22:36 153,088
drvstore.dll 6.3.9600.22819 12-Sep-25 22:36 744,960
dpx.dll 6.3.9600.22819 12-Sep-25 22:29 345,088
msdelta.dll 6.3.9600.22819 12-Sep-25 22:35 499,712
mspatcha.dll 6.3.9600.22819 12-Sep-25 22:37 46,080
cmiv2.dll 6.3.9600.22819 12-Sep-25 23:03 3,300,352
cmiaisupport.dll 6.3.9600.22819 12-Sep-25 22:32 3,154,944
cmitrust.dll 6.3.9600.22819 12-Sep-25 22:34 418,304
WcmTypes.xsd Not versioned 12-Sep-25 20:08 1,047
CbsMsg.dll 6.3.9600.22819 12-Sep-25 22:37 42,496
CbsCore.dll 6.3.9600.22819 12-Sep-25 22:30 1,608,704
TiWorker.exe 6.3.9600.22819 12-Sep-25 22:34 193,024
TiFileFetcher.exe 6.3.9600.22819 12-Sep-25 22:30 427,520
DrUpdate.dll 6.3.9600.22819 12-Sep-25 22:36 246,784
wrpint.dll 6.3.9600.22819 12-Sep-25 22:29 66,048
wcp.dll 6.3.9600.22819 12-Sep-25 22:36 2,855,424
cmiadapter.dll 6.3.9600.22819 12-Sep-25 22:32 139,264
smiengine.dll 6.3.9600.22819 12-Sep-25 22:25 922,624
smipi.dll 6.3.9600.22819 12-Sep-25 22:34 65,536
poqexec.exe 6.3.9600.22819 12-Sep-25 23:15 146,432
amd64_installed Not versioned 12-Sep-25 20:06 9
bfsvc.dll 6.3.9600.22819 12-Sep-25 22:30 85,504
timezoneai.dll 6.3.9600.22819 12-Sep-25 22:35 101,888
GlobalInstallOrder.xml Not versioned 12-Sep-25 20:09 1,249,919
luainstall.dll 6.3.9600.22819 12-Sep-25 22:34 53,248
fveupdateai.dll 6.3.9600.22819 12-Sep-25 22:33 61,952
ExtendedSecurityUpdatesAI.dll 6.3.9600.22819 12-Sep-25 23:00 215,040
mofinstall.dll 6.3.9600.22819 12-Sep-25 22:34 67,072
esscli.dll 6.3.9600.22819 12-Sep-25 22:33 388,608
mofd.dll 6.3.9600.22819 12-Sep-25 22:33 248,320
repdrvfs.dll 6.3.9600.22819 12-Sep-25 22:33 350,720
fastprox.dll 6.3.9600.22819 12-Sep-25 22:33 854,016
wbemcomn.dll 6.3.9600.22819 12-Sep-25 22:34 453,632
wbemcore.dll 6.3.9600.22819 12-Sep-25 22:32 1,148,928
wmiutils.dll 6.3.9600.22819 12-Sep-25 22:34 111,104
wbemprox.dll 6.3.9600.22819 12-Sep-25 22:33 35,840
wmicmiplugin.dll 6.3.9600.22819 12-Sep-25 22:29 508,928
sppinst.dll 6.3.9600.22819 12-Sep-25 22:29 769,024
cmifw.dll 6.3.9600.22819 12-Sep-25 22:32 97,280
FirewallOfflineAPI.dll 6.3.9600.22819 12-Sep-25 22:36 166,912
NetSetupAI.dll 6.3.9600.22819 12-Sep-25 22:35 65,024
NetSetupApi.dll 6.3.9600.22819 12-Sep-25 22:36 184,832
httpai.dll 6.3.9600.22819 12-Sep-25 22:27 55,296
peerdistai.dll 6.3.9600.22819 12-Sep-25 22:27 65,024
PrintAdvancedInstaller.dll 6.3.9600.22819 12-Sep-25 22:36 99,328
msdtcadvancedinstaller.dll 6.3.9600.22819 12-Sep-25 22:27 215,040
netfxconfig.dll 6.3.9600.22819 12-Sep-25 22:48 40,448
ConfigureIEOptionalComponentsAI.dll 6.3.9600.22819 12-Sep-25 22:27 76,800
IEFileInstallAI.dll 6.3.9600.22819 12-Sep-25 22:24 66,560
servicemodelregai.dll 6.3.9600.22819 12-Sep-25 22:27 96,768
SetIEInstalledDateAI.dll 6.3.9600.22819 12-Sep-25 22:27 49,152
ceipfwdai.dll 6.3.9600.22819 12-Sep-25 22:25 197,632
bcdeditai.dll 6.3.9600.22819 12-Sep-25 22:28 271,360
appxreg.dll 6.3.9600.22819 12-Sep-25 22:43 19,968
RegisterIEPKeysAI.dll 6.3.9600.22819 12-Sep-25 22:26 23,040
cmipnpinstall.dll 6.3.9600.22819 12-Sep-25 22:47 195,072
securebootai.dll 6.3.9600.22819 12-Sep-25 22:28 175,104
winsockai.dll 6.3.9600.22819 12-Sep-25 22:27 71,680
ws2_helper.dll 6.3.9600.22819 12-Sep-25 22:28 50,176
cleanupai.dll 6.3.9600.22819 12-Sep-25 22:27 37,376
wdscore.dll 6.3.9600.22819 12-Sep-25 22:28 208,384
CntrtextInstaller.dll 6.3.9600.22819 12-Sep-25 22:29 128,000
drvstore.dll 6.3.9600.22819 12-Sep-25 22:29 610,304
dpx.dll 6.3.9600.22819 12-Sep-25 22:24 265,216
msdelta.dll 6.3.9600.22819 12-Sep-25 22:28 398,336
mspatcha.dll 6.3.9600.22819 12-Sep-25 22:30 36,864
cmiv2.dll 6.3.9600.22819 12-Sep-25 22:48 2,257,408
cmiaisupport.dll 6.3.9600.22819 12-Sep-25 22:26 2,162,688
cmitrust.dll 6.3.9600.22819 12-Sep-25 22:28 286,720
WcmTypes.xsd Not versioned 12-Sep-25 20:15 1,047
CbsMsg.dll 6.3.9600.22819 12-Sep-25 22:30 41,984
CbsCore.dll 6.3.9600.22819 12-Sep-25 22:25 1,381,376
TiWorker.exe 6.3.9600.22819 12-Sep-25 22:27 190,464
TiFileFetcher.exe 6.3.9600.22819 12-Sep-25 22:25 355,328
DrUpdate.dll 6.3.9600.22819 12-Sep-25 22:29 202,240
wrpint.dll 6.3.9600.22819 12-Sep-25 22:25 56,320
wcp.dll 6.3.9600.22819 12-Sep-25 22:30 2,408,960
cmiadapter.dll 6.3.9600.22819 12-Sep-25 22:27 121,856
smiengine.dll 6.3.9600.22819 12-Sep-25 22:22 750,080
smipi.dll 6.3.9600.22819 12-Sep-25 22:27 59,904
poqexec.exe 6.3.9600.22819 12-Sep-25 22:58 129,536
x86_installed Not versioned 12-Sep-25 20:12 9
bfsvc.dll 6.3.9600.22819 12-Sep-25 22:26 81,920
timezoneai.dll 6.3.9600.22819 12-Sep-25 22:29 86,528
GlobalInstallOrder.xml Not versioned 12-Sep-25 20:15 1,249,919
luainstall.dll 6.3.9600.22819 12-Sep-25 22:28 43,008
fveupdateai.dll 6.3.9600.22819 12-Sep-25 22:27 57,344
ExtendedSecurityUpdatesAI.dll 6.3.9600.22819 12-Sep-25 22:45 177,664
mofinstall.dll 6.3.9600.22819 12-Sep-25 22:28 64,000
esscli.dll 6.3.9600.22819 12-Sep-25 22:27 293,376
mofd.dll 6.3.9600.22819 12-Sep-25 22:27 204,800
repdrvfs.dll 6.3.9600.22819 12-Sep-25 22:27 277,504
fastprox.dll 6.3.9600.22819 12-Sep-25 22:27 670,208
wbemcomn.dll 6.3.9600.22819 12-Sep-25 22:27 386,048
wbemcore.dll 6.3.9600.22819 12-Sep-25 22:26 925,696
wmiutils.dll 6.3.9600.22819 12-Sep-25 22:27 90,624
wbemprox.dll 6.3.9600.22819 12-Sep-25 22:27 29,696
wmicmiplugin.dll 6.3.9600.22819 12-Sep-25 22:24 392,704
sppinst.dll 6.3.9600.22819 12-Sep-25 22:24 646,656
cmifw.dll 6.3.9600.22819 12-Sep-25 22:26 80,896
FirewallOfflineAPI.dll 6.3.9600.22819 12-Sep-25 22:29 140,800
NetSetupAI.dll 6.3.9600.22819 12-Sep-25 22:28 55,296
NetSetupApi.dll 6.3.9600.22819 12-Sep-25 22:29 124,928

References

Servicing stack updates

Servicing Stack Updates (SSU): Frequently Asked Questions

ADV990001 | Latest Servicing Stack Updates

Description of the standard terminology that is used to describe Microsoft software updates