Ok. Hey everybody I haven't been back for a while since I purchased my Vista 64 bit quadcore. I'm very happy with it. No problems. But that is not why I am here today.
My brother's computer is very outdated (about 7 years I think). He has an
Asus P4R800-VM with an
intel pentium 4 2.8 and some haggard video card that was the minimum requirement for BF2 to play back in the day...an
ATI Radeon 9600XT.

The hard drive is a WD800 or whatever (
Western Digital 80GB). His ram isn't helping his situation by only being
512mb at 400mhz Kingston.
So his computer hasn't had many problems in these past years...only a power supply replacement twice I think (cuz he buys crappy ones). I always tell him to buy 1 antec for life.
I
uninstalled and reinstalled his
Windows XP Pro formatting (not quick). Everything is laddyda for a little bit when ALL OF A SUDDEN his computer starts to freeze constantly and we began to think it was only when he ran iTunes or tried to play a video on youtube...
This is a fresh instalI with a normal (not quick) format. I tried adding a stick of 256 the same kind + same mhz and he got a beep code (no boot) so we took it out and it ran. To be sure there were no problems with the current stick, tried running memtest86 for 7 passes and it was good. So I start to think it's the CPU going or something with the motherboard if anything, since the HD doesn't make any disturbing noises.
Still trying to monitor the freezing, the occurences become more and more confusing and sporadic. It began to freeze when just on facebook or at Asus website to download drivers (idiot decided to do another fresh install because hes an idiot). Anyway, he got these 2 short beeps a little bit after he got it going again (when installing drivers). That stands for "Parity circuit failure" which have many different associated problems. Does that mean it's his motherboard?
His computer booted again no problem this time and got a
new problem where when it froze, the screen shut off and went to "no signal" and the computer just hung there. Since he's broke cuz he's having car problems and a student, he can't buy a new computer which was my suggestion. If he has any money to spend it has to be on the one right part that will fix it and I say processor. How do you know for sure? His usage is at 10-15% with youtube, facebook, aim, and itunes on. All fans inside case are clean, including processor fan and gap in between. He has NEVER gotten a
blue screen.
What do you guys think?
If you got this far, I thank you for your patience. 
I am going on vacation for Daytona bike week tomorrow if any of you are motorcycle fans...so any replies will go directly to my brother (hes intermediate- I've been running him through it and he has done everything himself so he'll be able to follow instructions if any). Thanks a lot guys I really appreciate it!