steelGrunt[...] windows was just installed yesterday.
Do you have a firewall, and did you download and install the security updates ?
I'm pretty sure it's the PSU. Like I said, do you have a spare?
Well before opening the case and voiding any warranty, I guess we should at least check if the OS is not faulty, or if it is indeed a hardware problem which may be determined without opening. So it's better to run a few diagnostic / testing tools before, as already suggested by -StaticX- ...