Fix a corrupt profile

Corrupt user profiles are a frustratingly common problem with Windows and there are various problems and solutions depending on the exact error message you receive. Here we show you how to recover from a corrupt user profile by either fixing the problem or creating a new account and transferring your user data across to the new profile.

See also: Windows 8.1 review

When you type your password and press Enter, you will typically see the error message “The User Profile Service failed the logon” and “The user profile cannot be loaded”, and you’ll be returned to the logon screen.

WARNING: Some people have lost files by using Method 1 below, so create a backup of your hard disk, or just files you cannot afford to lose before trying anything which involves editing the Windows Registry. There are various programs which will allow you to make a copy of your entire disk, but you will need a second disk with sufficient capacity, and may even need a second PC or laptop in order to copy the disk (if you can't boot into Windows). You should also make a backup of the Registry itself from Safe Mode before you start. These instructions are provided as a last resort, and we recommend you try Method 2 - below - before trying Method 1.
Method 1: Fix a corrupt profile

Microsoft says that a user profile can become corrupted if your antivirus software is scanning your PC while you try to log on, but it could also be caused by other things.

A quick fix can be to restart your PC, but if this doesn’t work you’ll need to restart again and boot into Safe mode. Do this by pressing F8 before you see the Windows loading screen and choosing Safe Mode from the menu that appears.

Safe Mode logs you into the built-in Windows administrator account, but you might find that some options don’t work.

The User Profile Service failed the logon

Step 1. To fix the user profile, click Start and type regedit into the search box and press Enter.

Step 2. Registry Editor will launch and you need to navigate to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

Step 3. Click each S-1-5 folder and double-click the ProfileImagePath entry to find out which user account it relates to. (If your folder name ends with .bak or .ba follow Microsoft's instructions to rename them.)