I run Windows 7 on my Dell Dimension E510 with an 80G sata hd. I added a 300G sata hd for movies, music, etc...I decided to install XP Pro on the 2nd hd (300G) to make a dual boot machine. Having no clue how to do it I figured I would learn from mistakes. I can only boot to the XP drive now. Once booted I can see the 7 drive. If I unplug the XP drive, I get a BOOTMGR error and can't do anything. Please help this noob fix the problem. Thank you in advance for any help.