I run Windows 7 on drive C and Vista on drive E. Both running well. I have a spare empty partition drive G on which I wanted to install XP Pro. A techie friend said there would be no problem simply running the XP Pro disk and installing to the empty partition. He was wrong.
XP Pro installed okay but both Vista and Windows 7 had vanished from the boot up screen. The computer was logging straight into XP like it was the only show in town.
I had to use the Repair option on my Windows 7 disk to get both Windows 7 and Vista back on the boot up screen. Problem is, XP has now disappeared from the boot up screen - the option to boot into XP is simply not there.

What is my best course of action?