hello people,
    my computer woulod trip off most times ,i mean it doesnt shut itselfe down the normal way that pc would shut down ,it would just trip off and both the MONITOR and the cpu  would stop instantly, when this happen and i press the start up button on my cpu cabinet ,the pc would not start ,however if i swithc off the pc from the main switch and switch it on after about 5 seconds ,then the pc would start when i pressthe start up button on the cpu,but after booting up the pc would also do the same thing and shut itself down in about 2 to 5 mins of booting up ,the only way i COULD use the pc after this shut down is to leave it to "cool" down for about 10 to 15 mins ,
   after this interval the pc would start working normal again ,i have noticed that this problem happens 90% when the pc have been on for several hours ,like 7 to 10 hours ,the problem also happens when i try to scan my pc with any type of anti virus or antispyware ,it also happens when i open multiple websites while using the internet or when my pc became frozen,
     when this happens and i wont be able to get the pc to work unless i have to wait for 10 to 15 mins for it to "cool" down ,i tried to boot the pc in safe mode ,but still it shut down again ,so i have come to think that something always gets "heated" when ever the pc have WORKED for several hours or while i do scan for virus or spyware and would "cool" down only i LET the pc rest for few mins ,this led me to think that it might be hardware problem,though i dont know what it could be ,and ofcos i could be all wrong .
     also sometimes this very problem would disappear for about a month or so and then come back again,i have formated my hardrive times without number yet it didnt solve this problem,i upgraded my pc from 256 mb ram to 512 yet to no avail ,i have also removed several programs to free up the pc and still it didnt stop .
    i also suspect that the problem might be from the power supply and the fan ,cos i thought they might be getting overheated,but as i said am not too expert on these ,so i might be wrong ,
    i have windows xp professional with sevice pack 2,my pc specifications are INTEL(R) CELERON(R) CPU 1.7GHz

    i would realy apprechiate any help to solve this problem ,thanks and looking forward for some help .

DanielAre the PC case and heatsinks dust free? Quote

Are the PC case and heatsinks dust free?

Quote

Are the PC case and heatsinks dust free?

i have used some pc cleaner to flush out all the dust from the pc sometimes back ,but it didnt stop the problem , and what is heatsinks
?