Heather, do us a favor here and on your desktop, click START and then click RUN. In the box that pops up, type in "dxdiag" without the quotation marks, and press Enter or OK.
Now, once it finishes doing what it's doing , go to the bottom right corner of the window and click "Save all information...", and give it a name and save it on your desktop or My Documents or whatever.
Then, when you respond to this post, attach the file that you just made by using the paperclip icon in the top toolbar of the post window.
Doing this will help everyone here understand your problem just a little better. Also, if you have any programs that you use to get rid of spyware and malware, update and run them (it's probably not a virus issue, but it's best to be sure).