I installed a 9250 video card and now my computer is slow and it refreshes very slow with a wavey line that comes down the screen and when i play a video it flashes with a line coming down

It seems that your video drivers are not properly installed or some of the files are corrupted. You can try un-installing the video card driver, rebooting, and then re-installing it.

Here's an easy way to download and install / update your video card drivers:

Use this driver scanning tool, which scans your computer for the needed drivers. It has an option to automatically retrieve the drivers for you.

You can download this free driver scanning tool from here: http://xpdrivers.com/index.cfm or directly from this link: http://xpdrivers.com/download/download.cfm (copy/paste the link into your browser, if you can't click it).

After you have downloaded the above file, double-click on it and follow the simple steps to install it. Then, when it asks if you want to run it, just answer yes. This is easier than manually searching, downloading and installing the drivers.

For Windows XP Driver Files and How-to Resources, visit http://xpdrivers.com

Hope that helps,
Regards,
Raspal