I can't get windows vista to boot?

I am trying to set my computer up to dual boot between vista and xp, vista. being the main/original os for my system. Following directions from websites I made a partition installed xp, and had my vista disk ready because I was told that installing xp would mess up the bootloader for vista and I needed to pop In the disk choose to boot it first and then go to an option called startup repair. Well I did that, and it told me it was unable to fix the problem. I can't load vista, but I can load xp. Unfortunatly I has 't installed my drivers for my wi fi card or my Ethernet card. I am on my iPod touch typing this and will go search the web, but any help would be appreciated.