Reinstall XP with Win 7 pre-installed

I had Win XP crash on me, so I had to reinstall it. I had previously install Win 7 with XP already installed, and had been using the bootloader choose OS on start.
But now that I have had to reinstall XP, I have lost the bootloader. How do I get this back so I can get back into Windows 7.
Thanks
Answer #1
Get VistaBOOTPro