Windows · Windows Server  ·  high  ·  Core Windows faults

"The User Profile Service failed the sign-in"

Windows cannot load the profile, so it either refuses the sign-in or drops the user onto a temporary desktop with none of their files.

What you see

Sign-in fails with the profile service message, or succeeds into a blank desktop with a "You've been signed in with a temporary profile" notice.

What is actually wrong

The ProfileList registry key for that account is damaged — usually a .bak suffix left behind, or a ProfileImagePath pointing at a folder that has been renamed or deleted.

Codes and articles

User Profile Service failed the sign-inEvent 1511Event 1500Event 1542

Fixes (2)

Repair the ProfileList entry
Elevated PowerShell, signed in as a different administrator15 minutesmedium riskreversible

The user's folder still exists under C:\Users. Sign in as another administrator — you cannot repair a profile you are currently using.

  1. List the profile entries and find the one for the affected user. Note whether its key name ends in .bak.

    PowerShell
    Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList' | ForEach-Object { [PSCustomObject]@{ Key = $_.PSChildName; Path = (Get-ItemProperty $_.PSPath).ProfileImagePath } }

  2. Export the whole key as a backup before touching it.

    Command Prompt
    reg export "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList" C:\temp\profilelist-backup.reg

  3. If there is a matching pair — S-1-5-21-… and S-1-5-21-….bak — delete the one WITHOUT .bak, then rename the .bak key to remove the suffix.

    Windows creates the .bak when it fails to load the real profile. The .bak is the good one; the plain key is the temporary profile it made instead.

  4. In the surviving key, set RefCount and State to 0.

    PowerShell
    $sid = 'S-1-5-21-REPLACE-ME'$k = "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\$sid"Set-ItemProperty $k -Name RefCount -Value 0 -Type DWordSet-ItemProperty $k -Name State -Value 0 -Type DWord

  5. Confirm ProfileImagePath points at the real folder, then restart and sign in as the user.

    PowerShell
    Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\$sid" | Select-Object ProfileImagePath, RefCount, State
Confirm it workedThe user signs in to their own desktop with their files present, and no temporary profile warning appears.
If you need to undo itImport the .reg file exported in step 2 and restart.
Create a fresh profile and migrate the data
Windows30–60 minutesmedium riskreversible

The profile folder is gone or the registry repair did not take. Do not delete the old folder until the new profile is confirmed working.

  1. Sign in as another administrator.

  2. Rename the old profile folder rather than deleting it.

    PowerShell
    Rename-Item C:\Users\olduser C:\Users\olduser.broken

  3. Delete that user's key under ProfileList (export it first, as above).

  4. Sign in as the user. Windows builds a clean profile.

  5. Copy data across — documents, desktop, pictures, downloads, and AppData selectively.

    PowerShell
    robocopy C:\Users\olduser.broken C:\Users\olduser /E /XJ /R:1 /W:1 /XD AppData

    AppData is excluded deliberately: copying it wholesale is the most common way to drag the original corruption into the new profile. Bring individual application folders over only if something is missing.

Confirm it workedThe user has a working desktop and their documents are present.
If you need to undo itThe original data is still in C:\Users\olduser.broken until you remove it.

Related faults

Signed in with a temporary profile — "You've been signed in with a temporary profile"Windows

Where this stops. This write-up was written and checked by hand. It says what each step changes, how to confirm it worked and how to reverse it, and anything destructive is flagged before you reach it. If it does not match what your machine is doing, search the Support Centre for the exact code or message — and when something needs a person, get in touch.