Cant figure this one out

Squall

Ive been having problems with my PC for awhile.

Heres a list of the problems:
It freezes on bootup at random points
I get blue screens (also randomly).
When it does bootup successfully it freezes (again randomly).
When a freeze occurs and I reset it powers down but doesnt actually reset. Again when a freeze occurs holding in the power button does nothing (Its set to shutdown if pressed for 5 secs).

Couple of things ive noticed:
When it freezes my optical mouse loses power.
If it enters sleep state it freezes
It can boot up successfully and run just fine but its rare

I first thought it was a harddrive problem but ive tested other working drives and it still occurs with those. I havent installed any new hardware recently either. Oh and ive tested the cables too and those seem fine.

Right now im thinking its a power problem. The PSU isnt sounding too healty and the weird mouse, reset button and power button problems are making me lean that way. Any way of testing that theory? I dont want to replace the PSU only to find its something else causing it. Anyone have any idea of what else it might be?

Driving me nuts and im now without my own PC

Jammer

freezing randomly, and the blue screens suggest a possible RAM problem, if possible try boot with different sticks...

the optical mouse suggests possibly a psu problem, or it all could add up to a possible motherboard fault.

Try different RAM, and/or PSU....

Squall

RAM seemed fine. Gonna try and get my hands on a replacement PSU today. Im hoping its not a motherborad problem