I'm running WinXP and decided to have a look at Vista to check if it was compatible with my system and to try out any drivers that are available just to see if it was worth upgrading. Sadly altho' it's very pretty it's not worth the hassle as the most important thing, my BT Voyager 2091 wireless Modem/Router will not work with it (Keeps saying 'unable to connect to 192.168.1.1' which is the standard for setting up the Modem I believe. Anyway I booted into XP and re-formatted the drive I'd installed Vista on. The problem I have now is I'm still getting the boot option screen to boot either Vista or XP. I've looked at the Boot.ini file in XP but it is set as the only O/S. I guess there must be another hidden file or registry key somewhere that needs modifying. Any ideas appreciated.
As Pineman said above but do fixboot first then fixmbr. After rebooting into XP go to My Computer and click on drive C. Delete the two files Boot.BAK & Bootsect.BAK (vista installed these and are no longer needed).