Hello everyone!

I have a such a problem. I have got hardwares 80GB and 40 GB and when they
are
both connected or one of them is connected to computer, while computer
working
suddenly computer is rebooting. It appears only when I do some operations
on computer and for example I do many operations at the same while. When
computer works during a night and I do not work on the computer in this
time,
then it can work all the night.
Can you help me what elements of my computer makes this problem with
rebooting? What did it caused? The problem appears after I bought hardware
80GB SAMSUNG 7200 turns, but even this hardware is disconnected from
computer and then I connect 40GB hardware, the problem also appears.

Thank you in advance for your help
Best regards
Marcin from Poland