This is an occasional problem when attempting to reinstall Vista using a factory restore option, in cases where the original boot environment has been modified using bcdedit, as used by VistaBootPRO. This is not a problem with the software, but with the factory settings - particularly in machines that may have hidden partitions.
Basically, the factory restore option just assumes (sometimes erroneously) that the factory boot environment still exists, whereas Windows setup itself does not, nor does the boot environment installed, thereby creating a discrepancy in the database.
I would suggest the following --
1) reinstall XP, simply to restore bootability.
2) borrow some Vista installation DVD from somebody or somewhere -- your manufacturer's failure to provide Vista installation media not supporting XP retro-compatibility is a contractual violation on their part, so that any reasonable efforts on your part to obtain alternative installation media can be morally justified (although you must use the Windows license purchased at the same time as the machine, or purchase a replacement license). Obtain the correct installation media, and install using the correct product key you have purchased, which is located on the sticker affixed to your machine by your OEM. You can borrow any Vista installation DVD -- unlike XP and W7, original Vista DVDs are not restricted to install only the Windows version described on the surface and packaging of the DVD.
(you can launch Vista setup from inside XP using a DVD of the 32-bit version -- boot into XP, insert your Vista DVD, launch setup, and choose the clean install option --
if you can manage to get the machine to boot to XP. In that case, it might be desirable to analyse the hard drive partitioning to check for potential issues prior to reinstalling Vista)
3) You can skip part 1) if you like, or if you have too many problems with XP
Just clean install using clean installation media and your product key -- if you can obtain such media (a DVD), this is by far the cleanest solution
4) If you have a hidden partition, it may be necessary to use a bootable CD or DVD to delete it, *provided* you were absolutely certain that your installation media were clean and functional. This problem is only likely to occur if trying to install from a clean Vista DVD were to fail, however given your current isues this is a distinct possibility.
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The alternative using VistaBootPRO is a little complex and delicate -- this would be an advanced functionality of the software.
Unfortunately, it would first require getting your system bootable again, which is precisely what you need in the first place !!
If you absolutely require some sort of IT perfectionist solution, we can certainly help -- but it's hardly recommended !!
DualBootPRO