WINDOWS 7 LOGIN PROBLEM-PASSWORD NOT RECOGNIZED

Hi, 

I have a HP 2009m desktop computer. When I used it last time, it worked well, and I shut it down at the end of use to save energy. This evening when I turned the computer on, it wouldn't let me logon. The screeen has a message: 

"The userProfile Service service failed the logon. User profile cannot be loaded."

Please, anyone out there, HELP.

Thanks in advance.

Pin