Guides from the
Windows Help Desk
Every guide follows our editorial policy: the exact problem first, the safest fix first, and clear notes on which versions it applies to.
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Windows Explorer crashes on right-click: how to find the cause and fix it
File Explorer or the desktop crashes when you right-click in Windows 11 or 10? Find the faulty shell extension in Event Viewer, disable it,…
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Sysprep was not able to validate your Windows installation: how to fix it
Fix “Sysprep was not able to validate your Windows installation” in Windows 11 and 10: read setupact.log, remove Store apps not provisioned for all…
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A required device isn’t connected or can’t be accessed (0xc000000e): how to fix it
Fix error 0xc000000e, “A required device isn’t connected or can’t be accessed”, in Windows 11 and 10: check the drive and boot order, undo…
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Failed to open a session for the virtual machine: VirtualBox fixes
Fix VirtualBox’s “Failed to open a session for the virtual machine” error: match the code in Details to the cause, then discard the saved…
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UsoClient StartScan: what it does and the other UsoClient commands
What UsoClient StartScan does, how to run it, the other UsoClient commands, how to tell whether it worked, and what to do when it…
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Automatic registration failed at join phase: what it means and how to fix it
Seeing “Automatic registration failed at join phase” in the User Device Registration log? Find out if it matters, how to stop it, and how…
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SFC offline: how to run sfc /scannow from recovery in Windows 11 and 10
Run SFC offline when Windows won’t start: open Command Prompt in recovery, find the right drive letter, and use sfc /scannow with /offbootdir and…
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Windows Update service missing: how to restore it in Windows 11 and 10
Windows Update service missing from services.msc? Check with sc query, scan for malware, run SFC and DISM, use System Restore or a repair install…
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Operating system loader failed signature verification: how to fix it
Operating System Loader failed signature verification is a Secure Boot error. Remove USB drives, restore the default Secure Boot keys, rebuild the boot files…
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This sign-in option is disabled: how to fix it in Windows 11 and 10
Windows says this sign-in option is disabled because of failed sign-in attempts or repeated shutdowns? Restart cleanly, use your password, wait out the lock…