Do I need a new video card?

[Soul Daddy]

Ugh. My computer was acting the fool for the past few weeks, and I finally had enough and did a complete disk format/partition over the weekend. Problem solved, it's working like new. The only issue that I've noticed is the graphical/refresh quality. When I scroll on web pages, it is quite choppy and slow. Same goes for video quality. If I try to enlarge the video in WMP or whatever other software, it is quite choppy and unwatchable, so I have to watch it in its native size, which is way too small.

I do have a different video card than what was originally purchased, but can't locate any software disc that might have come with it. I checked for and downloaded new drivers for the card, but that didn't seem to remedy anything. I'm pretty much a noob, so I have no idea what to try next. Any ideas? Thanks,