I just googled the message you got, and there is some good advice, although it sounds like it's a pretty involved fix.

Try this:

http://answers.microsoft.com/en-us/windows/forum/windows_vista-security/user-profile-service-service-failed-the-logon-user/4ed66b21-c23e-42f1-98b2-706dcf931fae

Also, thought I'd mention that my spell checker doesn't like 'googled'. I am surprised. That obviously has nothing to do with your problem, but you never know when this information might be useful!