Problem with window can not load window profile.

Hi all,
We are using window server 2008 R2(runing terminal service) on HP server . The usage of CPU and Memory is just as normal.
But when I logon the server via RDP i got the message " The user Profile service service failed to logon User profile cannot be loaded". When i restart the server then i can get rid of this . But then the problem happen again when i logon. If i logon by my admin account i got the message in Event log " window cannot load the users profile bus has logged you on with the default profile for the system." It seems something corrupt may be the NTUSER.DAT file.
Can anyone address any solution for this ?

Thank you