Hardware malfunction: Computer freezes / shuts down

[Delythien]

I had my previous computer for about 10 years without switching out any component.

This year I bought myself a new computer and gave my old one to my girlfriend.
Computer specs:
- Processor: AMD Phenom(tm) II X4 810 Processor, 2608 Mhz, 4 Core(s), 4 Logical Processor(s)
- Graphics card: Nvidia GeForce GTS 250
- Motherboard: ASUS M4A78T-E AM3 AMD 790GX HDMI ATX AMD
- Memory: 2x Team Xtreem 2GB 240-Pin DDR3-1600 (PC3 12800)
- Hard Drive: 2x 200 GB HDD (can't remember the brand)

In the last 1-2 years my computer started to randomly freeze, shut down or just pop the blue screen of death.
I thought it was probably some software issue or something as I hadn't formatted my hard drive in around 4 years, plus the errors weren't that common.

Now that my girlfriend has the computer (freshly formatted) these freezes and shut downs still occur. I had my suspicions that some component might be faulty, but this pretty much raises the attention. I've tried reinstalling the Windows just to be sure, but it happens again.

There doesn't seem to be any specific pattern when this happens. It happens simply if you're writing something in Word, or if you're browsing the Internet, or playing a game. Either way, I don't believe it's connected with overheating.

So I wish to solve this issue so that the 'new' computer my girlfriend now has (and yes, it's a huge improvement over the one she had before that), so she can use it without any such problems.

My question is what can I do to find the source of this issue? Which components are worth checking? How do I check if they're faulty (like Memory test) -- do you know any programs I can check?
If we find the issue, hopefully changing that component will solve it.

Thanks for the help.

 

[Delythien]

In case it matters, I did fully clean the computer before giving it to her, and I reapplied the thermal paste for the processor.

 

[uberman]

On an old machine, considering you cleaned it and fresh windows install, probably a failing PSU or hdd. Power supply would be my first guess.

 

[Delythien]

How can I check if it's either PSU or HDD's fault for such behavior? I don't have any extra PSU to see if it works on that one.

Also, if anyone else has an idea what might be wrong, do tell.

 

[uberman]

Unfortunately the PSU is hard to check but if you can find a used one that works or an inexpensive one with enough wattage they are easy to swap. A dying one can fry at any time and possibly take other components with it. Your symptoms indicate that that might be the problem. 10 years is old for a PSU and many out subpar ones would have already failed by now so you have done well. On the Hdd a program like speccy can give you details about the machine without taking it out and looking at it. Find manufacturer and model then go to the website and they usually have tests to check health. Backup anything you want to save off it right away though. A dead hd will lose data and your OS but that isn't as bad as a fried PSU and that would be the first concern.

 

[Delythien]

Assuming we'd be willing to buy a new PSU for her computer, what would I be looking for? I don't have a clue about PSU's and don't want to pick one at random. Looking for a decent one with proper amount of Watts for the specifications from the first post.

 

[uberman]

Don't know where you live and whats available but check some sites like Newegg, Amazon, PC partpicker for something in your price range. Around 450 to 500 watts should be good for that machine. Read some reviews . Don't buy one just because its the cheapest. Maybe a local shop has a good used one for sale.