I checked my port status at GRC and saw that 135 was open. I followed the steps located at:

http://www.updatexp.com/dcom-windows-xp.html

and everything went swimmingly. So I went back to GRC, rescanned and it was still open! In my system configuration utility, it is called an essential service that I can't uncheck and it shows it is still running!

Any suggestions?

Thanks for your help!