In my efforts with Vista I keep encountering some nagging issues.  My latest was on one of my laptops; when logging in, I am prompted with an error: “The User Profile Service failed the logon. User profile cannot be loaded.” Luckily for me, I was able to piece enough information together to get it resolved.  Now, I hand the resolution over to you.

NOTE: Editing the Registry incorrectly can cause serious, system-wide problems that may require you to re-install Windows Vista to correct them. Microsoft nor computingondemand.com cannot guarantee that any problems resulting from the use of Registry editing can be solved. Back up your registry first, but use at your own risk.

• Restart your computer and log into safe mode: As your computer is rebooting, press F8 Repeatedly after your POST screen.

• Run “Regedit”: (If you are prompted for an administrator password or confirmation, type your password, or click Continue.)
• Locate the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
• You should see a few folders in the tree that are in the format: S-1-5-XXXXX.  If one of the longer of the bunch has a .bak on it your profile is in a backup status and can be fixed without being deleted. If you click on the folder with the .bak extension you will see an entry in the right pane that has the path to your logon user.