Windows Boot Manager

I think someone on this site told me about this software.
I need a Boot Manager to be able to boot between XP and Vista
I have Vista on one disk and XP on another but I can only boot into Vista

Thanks!

u mean each one on a hard drive??

or disc??

i had each one on a hard drive, and when i logged on to vista it worked all normal, and i tried to get into xp and it said error loading OS

each is on it's own separate hard drive