About 3 three months ago, my parents sent my computer to some dodgy man so he could add some RAM. When he sent it back, it immediately stopped working, so we sent it back to him. He said that the power supply failed. When we got it back again, I noticed that the computer seemed a little bit quieter.
Recently, my computer has become unbearably slow and and crashes frequently. It's becoming a real problem.
I know it's not my OS or software because I haven't installed any new software for some time now and I always run virus checks, etc.
A couple of days ago, I went into my computer's BIOS on statup and saw that the fan was running at around 5000rpm, but my CPU's temperature was 75C. That seemed a little higher than what it was before (45 - 55C) .
I opened up my computer case (Installing a NIC), and found that there were only 2 fans(1 CPU, 1 PSU), instead of the 4 that were previously there. Could this be the cause of my computer crashing?