1st tip should be:
GET A NEW COMPUTER .
2nd tip shall be: SAY FU** YOU TO W7/VISTA
3rd tip should be: GET A NEW CPU AND RAM, BIACH!
although, for my neighbor i runned everest and i found one error on his system, no program helped, guess what was wrong ? HD fan was spinning 1% speed, and HD just overheated and crashed, HD would be fked off if it would stay like that longer. I just edited HD's speed with fanspeed and now it's like hell fast, cause ram was 1gig and CPU 2,2GHZ DUO , everything should be just fine , kinda new comp too like few months...
(PS THE FIRST TIP WORKED FOR ME HEHE
. 8yrs old 256mb ram 128mb video, DD1 ram noway i will upgrade it, 1,75GHZ core one :L , now it stays on my parents room, living-room C: )