Tried helping my sister replace her video card on HPm9552p 64bit Vista, Home Premium Computer. The old one started making a loud noise which turned out to be the video card fan. Her monitor was displaying fine but game was running sooo slow before I took it out. I tried to put back in to see if the noise would stop, that maybe something was loose. Now the screen says no display. I took it back out and looked at it even closer and noticed a spot that looked like it was overheating. it was dark brown. We purchased a new video card and the display says the same thing. I'm afarid to ask this question, but in helping her did I mess up her computer? Thanks for any help anyone can give.