Vista Help: User Profile Service failed the logon

My brother just had this problem where he was not able to log on into his Vista Home premium notebook. It happened when he accidentally shut down his notebook while the Dell utility was updating his machine. The next thing he knew, he got the following error message when he tried to log on to his machine.

The user profile service service failed the login. User profile cannot be loaded.

After stumbling around a little, I manage to help him restore the profile issue.

The solution was quite an interesting one actually. I suspected that there would be two possible problem. One would be corrupted profile file(s). The other might be a ‘corrupted’ registry entry for the profiles. I googled and found that the user profiles are stored in the “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList” folder in the registry. But in order for me to look into the registry, I’d need to actually log into the machine in the first place!

And that didn’t seem to be a problem actually. Logging in with Safe Mode works fine. In order to do that, just press F8 after booting up and it should prompt you with a menu to do a couple of things before booting. There, you can find the Safe Mode option. And just to mention too, there is actually an option for a Startup Repair. I was not too sure what that does and therefore didn’t want to mess with it yet.

So, Safe Mode it was and voila! It did log in and immediately after loading up Vista, it mentioned something about the profile failure (duh) and also something about it creating a default profile. Hmmm interesting. Perhaps it’s not a corrupted profile after all. So I immediately looked into the registry and found the “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList” key to contain a few list of profiles. Interestingly, there was two that had the same key name with one having a “.bak” appended to it. Suspicious.

Studying those two keys, the one with the “.bak” suffix had the image path with my brother’s profile name. Voila, this is it! Everything looks fine there. And doing a quick look into the actual image path location, the files seems intact. Nothing out of the ordinary there. So perhaps it’s just a registry problem.

I then quickly did some comparison into the two profiles and noticed a few difference, particularly theStateDWORD value of 8000 for the profile that is the one I want to be loaded. Compared to the rest which are 0 or 256. Perhaps 0 is a safe value… meaning not logged in. Thus, this was what I did.

1. Renamed similar profile key S-1-5-21-#########-##########-#########-##### (without the .bak suffix) to S-1-5-21-#########-##########-#########-#####.temp
2. Renamed the S-1-5-21-#########-##########-#########-#####.bak to S-1-5-21-#########-##########-#########-#####
3. Change DWORD value of State of the now S-1-5-21-#########-##########-#########-##### from 8000 to0.
4. Close Regedit and reboot.

And voila… it worked!

Phew… Anyways, if you have doubts, please do leave me a message here and I’m willing to guide you along since editing the registry can be quite daunting sometimes. 🙂