new Compaq Presario freezes in XP, how do i find the prob?

[fugly]

a few months new Compaq Presario SR 1500NX AMD Sempron freezes after a few minutes of use. maybe like 10-15 mins max, then just freezes and nothing works.

Manufactured & supported by HP

AMD Sempron (tm) 3000+
2.00 ghz, 192 mb of RAM
80 Gig HD

i dont think its ram cuz i tried another ram stick thats 512 mb and its the same thing! i dont get it, how do i find out what the problem is?

what do you all think? will reinstalling the windows work?

 

[Zoron]

Faulty power supply or something is overheating. Open the case up and see how long it runs while it's open.

 

[fugly]

Faulty power supply or something is overheating. Open the case up and see how long it runs while it's open.

and then what? its not my computer, its a friend's. so i dont have it right here infront of me. how do i find out what is exactly overheating? i had my pc overheating cuz of my power supply (it was 350W) but it wasnt freezing like this, it would simply just shut off. i got a 500W psu and no more problems!