Having video problems

Hey all,
Running on an 4 year old campaq (I know, I know, I didn't know any better at the time0 currently have 1g of corsair RAM, and am running an ATI 9900. Now, the system runs fine and dandy until I try to open up anything video related. Suddenly everything slows down to a screaming halt, and the mpeg/avi/video game suddenly takes up 100% system resources and I'm stuck. I've replaced the video card, updated drivers, and done 2 clean installs, I've also run off the onboard video off the motherboard, same problem. Just can't figure it out, thanks for your time,

Matt

 

We need more info,read this,skip the search part

http://forums.majorgeeks.com/announcement.php?f=22

 

Hey,Im so sorry about that. Read it and forgot a few things, heh.

Running on windows XP Home, Pentium 3 chipset, cant't remember the rest offhand as it's actually my father's system. Runningt an old Maxtor 40 gig Hard drive, don't remember the rpm offhand.

 

No problem ,thats why this was also in the announcement