Support for Windows 10 will end in October 2025
After October 14, 2025, Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes for Windows 10. Your PC will still work, but we recommend moving to Windows 11.
Summary
This update makes improvements to Windows setup binaries or any files that setup uses for feature updates in Windows 10, version 21H2 and Windows 10, version 22H2.
How to get this update
Install this update
To install this update, use one of the following release channels.
Available |
Next step |
No |
This update is not available through Windows Update. See the Update Catalog release channel. |
Available |
Next step |
Yes |
To get the standalone package for this update, go to the Microsoft Update Catalog website. To download updates from the Update Catalog, see Steps to download updates from the Windows Update Catalog. |
Available |
Next step |
Yes |
This update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows:
|
Prerequisites |
There are no prerequisites to apply this update. |
Restart information |
You do not have to restart your computer after you apply this update. |
Update replacement information |
This update replaces the previously released update KB5045523. |
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.
File name |
File version |
Date |
Time |
File size |
acmigration.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
488,968 |
AcRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
333,816 |
Appraiser.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,899,504 |
appraiser.sdb |
Not versioned |
18-Oct-24 |
23:24 |
2,455,993 |
AppraiserRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
215,520 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
323,072 |
cmi2migxml.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
147,424 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
347,136 |
csiagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
536,032 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
338,432 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
377,856 |
diagtrack.dll |
10.0.10586.10008 |
18-Oct-24 |
23:24 |
919,736 |
Dism.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
226,296 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
394,752 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
372,224 |
Facilitator.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
794,080 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
342,016 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
376,320 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
368,640 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
237,056 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
224,768 |
MediaSetupUIMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
13,847,024 |
migcore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
6,834,160 |
mighost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
249,848 |
migisol.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
119,800 |
migres.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
17,384 |
MigStore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
958,960 |
MigSys.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
325,104 |
Mitigation.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
247,792 |
MXEAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
259,064 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
339,456 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
380,928 |
offline.xml |
Not versioned |
18-Oct-24 |
23:24 |
38,899 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
383,488 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
356,352 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
358,400 |
AppXDeploymentServer-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
4,900 |
EdgeMigrationPlugin.man |
Not versioned |
18-Oct-24 |
23:24 |
923 |
edpnotify-replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
830 |
fveApi-replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
1,101 |
Edge.dat |
Not versioned |
18-Oct-24 |
23:24 |
12,288 |
EdgeMigrationPlugin.dll |
1.0.0.1 |
18-Oct-24 |
23:24 |
90,096 |
EdgeUpdate.dat |
Not versioned |
18-Oct-24 |
23:24 |
12,288 |
TileStoreMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
97,760 |
AppxUpgradeMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
380,904 |
iismig.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
312,816 |
SxsMigPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
109,576 |
PPIPolicies-General-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
2,161 |
PPIPolicies-Miracast-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
1,352 |
StartTileData-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
2,702 |
ReserveManager.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
217,592 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
355,840 |
Setup.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
244,224 |
setupcompat.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
293,856 |
SetupCore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,900,512 |
SetupHost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
704,520 |
SetupMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
768,520 |
SetupPlatform.dll |
1.60.19041.5123 |
18-Oct-24 |
23:24 |
7,232,480 |
SetupPlatform.exe |
1.60.19041.5123 |
18-Oct-24 |
23:24 |
153,072 |
SetupPrep.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
10,659,296 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
348,672 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
336,384 |
unbcl.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
837,104 |
uninstall.xml |
Not versioned |
18-Oct-24 |
23:24 |
3,508 |
UpdateAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,147,336 |
upgrade_bulk.xml |
Not versioned |
18-Oct-24 |
23:24 |
208,513 |
upgradeagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,418,680 |
WinDlp.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,103,464 |
winsetup.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,982,896 |
WinSetupBoot.sys |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
67,576 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
182,784 |
File name |
File version |
Date |
Time |
File size |
acmigration.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
658,440 |
AcRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
333,792 |
Appraiser.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
2,262,520 |
appraiser.sdb |
Not versioned |
18-Oct-24 |
23:25 |
2,759,183 |
AppraiserRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
216,048 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
323,072 |
cmi2migxml.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
192,520 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
347,136 |
csiagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
725,984 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
338,432 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
377,856 |
diagtrack.dll |
10.0.10586.10008 |
18-Oct-24 |
23:25 |
1,362,104 |
Dism.exe |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
289,288 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
394,752 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
372,224 |
Facilitator.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
1,024,504 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
342,016 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
376,320 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
368,640 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
237,056 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
224,768 |
MediaSetupUIMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
14,034,952 |
migcore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
9,097,736 |
mighost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
260,592 |
migisol.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
146,416 |
migres.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
17,376 |
MigStore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
1,271,280 |
MigSys.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
436,232 |
Mitigation.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
324,592 |
MXEAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
360,432 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
339,456 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
380,928 |
offline.xml |
Not versioned |
18-Oct-24 |
23:25 |
38,899 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
383,488 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
356,352 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
358,400 |
AppXDeploymentServer-Replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
4,900 |
EdgeMigrationPlugin.man |
Not versioned |
18-Oct-24 |
23:25 |
923 |
edpnotify-replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
830 |
fveApi-replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
1,101 |
Edge.dat |
Not versioned |
18-Oct-24 |
23:25 |
12,288 |
EdgeMigrationPlugin.dll |
1.0.0.1 |
18-Oct-24 |
23:25 |
114,696 |
EdgeUpdate.dat |
Not versioned |
18-Oct-24 |
23:25 |
12,288 |
microsoft-hyper-v-migration-replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
6,088 |
TileStoreMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
126,944 |
AppxUpgradeMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
470,000 |
iismig.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
377,824 |
SxsMigPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
134,152 |
PPIPolicies-General-Replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
2,161 |
PPIPolicies-Miracast-Replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
1,352 |
StartTileData-Replacement.man |
Not versioned |
18-Oct-24 |
23:25 |
2,702 |
ReserveManager.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
281,072 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
355,840 |
Setup.exe |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
294,368 |
setupcompat.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
385,504 |
SetupCore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
2,369,008 |
SetupHost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
885,232 |
SetupMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
989,680 |
SetupPlatform.dll |
1.60.19041.5123 |
18-Oct-24 |
23:25 |
9,594,888 |
SetupPlatform.exe |
1.60.19041.5123 |
18-Oct-24 |
23:25 |
171,016 |
SetupPrep.exe |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
10,872,816 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
348,672 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
336,384 |
unbcl.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
1,099,240 |
uninstall.xml |
Not versioned |
18-Oct-24 |
23:25 |
3,508 |
UpdateAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
2,806,256 |
upgrade_bulk.xml |
Not versioned |
18-Oct-24 |
23:25 |
208,513 |
upgradeagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
3,178,504 |
WinDlp.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
1,443,432 |
winsetup.dll |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
3,740,144 |
WinSetupBoot.sys |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
80,888 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:25 |
182,784 |
File name |
File version |
Date |
Time |
File size |
acmigration.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
673,776 |
AcRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
333,792 |
Appraiser.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,302,456 |
appraiser.sdb |
Not versioned |
18-Oct-24 |
23:24 |
1,947,882 |
AppraiserRes.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
215,544 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
323,072 |
cmi2migxml.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
205,304 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
347,136 |
csiagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
765,944 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
338,432 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
377,856 |
diagtrack.dll |
10.0.10586.0 |
18-Oct-24 |
23:24 |
1,561,952 |
Dism.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
322,568 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
394,752 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
372,224 |
Facilitator.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,092,080 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
342,016 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
376,320 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
368,640 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
237,056 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
224,768 |
MediaSetupUIMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
14,053,872 |
migcore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
9,820,144 |
mighost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
262,640 |
migisol.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
141,296 |
migres.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
17,376 |
MigStore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,342,984 |
MigSys.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
466,440 |
Mitigation.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
337,928 |
MXEAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
380,384 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
339,456 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
380,928 |
offline.xml |
Not versioned |
18-Oct-24 |
23:24 |
38,899 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
383,488 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
356,352 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
358,400 |
AppXDeploymentServer-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
4,900 |
EdgeMigrationPlugin.man |
Not versioned |
18-Oct-24 |
23:24 |
923 |
edpnotify-replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
830 |
fveApi-replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
1,101 |
Edge.dat |
Not versioned |
18-Oct-24 |
23:24 |
12,288 |
EdgeMigrationPlugin.dll |
1.0.0.1 |
18-Oct-24 |
23:24 |
122,336 |
EdgeUpdate.dat |
Not versioned |
18-Oct-24 |
23:24 |
12,288 |
microsoft-hyper-v-migration-replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
6,088 |
TileStoreMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
133,112 |
AppxUpgradeMigrationPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
502,280 |
iismig.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
391,152 |
SxsMigPlugin.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
144,368 |
PPIPolicies-General-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
2,161 |
PPIPolicies-Miracast-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
1,352 |
StartTileData-Replacement.man |
Not versioned |
18-Oct-24 |
23:24 |
2,702 |
ReserveManager.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
279,008 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
355,840 |
Setup.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
297,456 |
setupcompat.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
408,560 |
SetupCore.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,408,944 |
SetupHost.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
903,648 |
SetupMgr.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,040,880 |
SetupPlatform.dll |
1.60.19041.5123 |
18-Oct-24 |
23:24 |
10,374,112 |
SetupPlatform.exe |
1.60.19041.5123 |
18-Oct-24 |
23:24 |
175,072 |
SetupPrep.exe |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
10,918,920 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
348,672 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
336,384 |
unbcl.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,151,456 |
uninstall.xml |
Not versioned |
18-Oct-24 |
23:24 |
3,508 |
UpdateAgent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
2,980,336 |
upgrade_bulk.xml |
Not versioned |
18-Oct-24 |
23:24 |
208,513 |
upgradeagent.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
3,356,128 |
WinDlp.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
1,495,168 |
winsetup.dll |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
3,784,688 |
WinSetupBoot.sys |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
80,880 |
AcRes.dll.mui |
10.0.19041.5123 |
18-Oct-24 |
23:24 |
182,784 |
References
Description of the standard terminology that is used to describe Microsoft software updates.
Query words: Setup DU