When the subject of which version of Media Center someone is running there is often some confusion - this is because the version of the Media Center software and the Windows XP version are different.  To identify the version of Media Center you are running do the following:

  1. Start Media Center
  2. On the start page scroll down and select "Settings"
  3. Click "General"
  4. Now select "About Media Center" - it's right at the bottom of the list

If the version displayed is not "Windows XP Media Center Edition 2004" you're not running the 2004 release - contact the manufacturer of your PC (i.e. HP, Gateway etc.) and ask about getting an upgrade.