System hangs after several minutes of operations
Hi Mr. Siatkarze,
It may cause for different causes. It could be a virus problem or a hardware problem. First check your computer if there is any virus or malware is in it or not. If the scan does not get anything then it is a hardware problem. Now switch off the computer and disconnect the power and press the start button for at least 15 seconds. Your computer’s every capacitors would be discharged and now on your computer. Now see very carefully that your hardware’s which part is getting heated early. If you think that anything is unusual you should change that. If that is the processor than change the cooling fan.
First things first: a thorough virus scan. I use Microsoft Security Essentials, because it's free, and known to be very effective. But whatever you have should work. If you can't keep the computer on for long enough for this to finish, you might have to use drastic measures to do a scan…but just do the rest of my recommendations before then.
A few things you could check
1) When it's not frozen, go to task manager (ctrl +alt +del)
2) View CPU and RAM usage in the performance tab, if they are running high constantly I would say it's a background process, possibly a virus.
For more Information see My computer freezes after a few minutes? – Yahoo! Answers