Media Center When Users Directory On Separate Drive Frm OS

I have been using the common method of using an answer file to move the users directory to a different location while in audit mode in sysprep... pretty basic stuff ok, now the problem I am having is that once rebooted in oobe phase, after the users directory has been moved, there is now no more option for "Add features to Windows...." or whatever it is when you are trying to install a key for W/ Media Center... Is there anyway to have your users directory on a different HDD and still be able to install WMC? Thanks in advance for any suggestions.