Hello all

My computer seems to stop from time to time :
After the startup, the machine runs normally for a while. Then
everything is stopped. The computer won't respond to the keyboard,.the
mouse can be moved, the hard disk telltale lamp is off. All I have to do
is wait. Then everything returns to normal. I have tested successively
the RAM modules by removing one after the other.
I suspect the processor. How to make sure ? What else can be wrong ?