i'm really not sure what issues are related to each other so i'll list all including those that seem superficial and unrelated

system dual core 3.0 ghz 4 gigs ram c drive seagate 1 terrabyte d a 350 gig wd g another 1 terrabyte seagate
nvidia gforce 8600 vid card (samsung flat panel with hd tv (svid cable) as second moniotor cloned)

vista premium 64 bit norton 360

ok so main issues
random freezes with a specific charachyeristic, hitting reset does not reboot, theres no 1st system beep (i think the vid card initiating?) reset results in just a black screen
only holding the power button 10 seconds to power down then hit it again to power up works
i thought it was overheatting but techs said no but sometimes if i dont leave it off awhile it freezes on boot up at random

when its at its worse i lose the usb wireless kewyboard and mouse

other issues probably unrelated
firefox gobbles up ram (reinstalled firefox and java)
myspace and other login pages act weird having to relogin a few times before it registers i logged in
clicking home in myspace often results in it doing nothing but saying loading, clearing cache and cookies every 5 minutes helpsbut then have to relogin
if i close firefox instead, the process keeps running (and usimng more ram and up to 40% cpu)

another odd issue is i use pidgin for all im's and lately i get alot of myspace mood updates by im, mostly from freinds but not all


its been in the shop3 times for these issues (1st time though the c drive went bad completely)
there were no viruses found (doesnt nesacarily mean there were none though)

it tends to freeze up once a day at least but sometimes once it freezes it takes multiple attempts to get it to boot

the systems not even a year old so i dont think its hardware
i put in operating systems because i just was not sure where the issue lies