Dell Window Media Center / Xbox 360 - Setup Issues

I really need some help setting up my Xbox 360 to run with Media Center 2005 on my Dell Laptop.

I have the Media Center Extender Manager installed on my machine and when I go to add a new Xbox 360 I keep getting the following error
message after I have typed in my 8 digit code:

"A problem occured during Setup. Please run setup again. If the problem persists, contact your computer manufacturer for assstance."

Any help would be much appreciated.

Thanks, Neil