Vista - user profile not loaded

Hi there
I've got a recurring problem with Vista. When I turn the computer on sometimes, I enter my password and it loads a screen that doesn't have any of my settings on and then the error message 'user profile not loaded....' appears. I have viewed a fiew forums with posts about this problem and have followed the advice of restarting, F8, safe mode, system restore.
This solves the problem, but it keeps occurring every couple of weeks now.
I have also noticed that when I turn the computer off, a message appears about ccc.exe before it turns off. Not sure if this is related.
I'd really appreciate any ideas about a permanent fix for this as it's really frustrating having to do a system restore all the time.
I'm not particularly techy ( as you'll probably guess from the way I've written everything down!) so please keep it simple in the replies!!!
Many many many thanks in anticipation
Sally

Sorry - should have said - error message is " Your user profile was not loaded correctly! You have been logged on with a temporary profile." I am using a Sony Vaio and Vista Home Premium.
Thanks

It is Catalyst Control Center component -I've never hear this could cause this kind of trouble ,neverless if you suspect it uninstall it.

You have to answer yourself what kind "User profile service..." you have

classic:
The User Profile Service failed the logon. User profile cannot be loaded.

or non-typical
Rob Brooks-Bilson's Blog: Fix for Vista's: The User Profile Service service failed the logon. User profile cannot be loaded
(advices in comments also you have to check)

It is possible your problem is caused by any virus (because problem still come back) because scanning on allive system is not credible -many viruses can hide perfectly before protected software i suggest burn special LiveCD with antivirus Kaspersky Rescue Disk - Load Kaspersky AntiVirus 2009 Using DOS
burn it,boot it & scan