Vista / XP Dual boot issues

I have Vista Business on one hard drive, I disconnected this hard drive and installed XP media center on another hard drive. I need to boot and use the XP, but I do not have the option, my computer automatically starts to Vista. I have an option during startup to choose where to boot from (Not the option for Vista or XP, but I can choose the drive to boot from). Anyhow, when I choose XP it will start to load up, the freeze right before the welcome screen, where it says loading settings. Can some one please help me?

 

I was recently pointed to this article, haven't tried it but will be in the near future.
http://www.pro-networks.org/forum/about88231.html

 

Thank you for posting me in the right spot, the link by colemanguy worked well. Thank you, I don't know if Vista is causing the issue, but the Welcome screen on XP still keeps freezing and will not load up. Will I have to reload XP or is there a way to fix this?