My computer freezes randomly, what can I do to fix this?

I tried to run check disk and it retuned no errors or bad sectors. I also run CCleaner and also no effect.

What else can I do to determine the problem and solve it?

OS: Windows 7

I installed different application for data recovery and uninstalled them.
Also I uninstalled any application that I installed recently

EDIT:
I need to do hard reset to get out of freeze state

EDIT1:
In safe mode it doesn't freeze

EDIT2:(Solved)
I disabled all the services and the programs that loads on startup accept for security & microsoft services. My computer worked all night without freezing!