hi i installed windows vista on my COMPUTER but kept xp on aswell it worked fine switching from one to the other till i switched on computer today and it said i have 2 files named c would i like to change one i said yes it restared computer but only blue screen came up now cant even reboot from xp disc just KEEP getting xp logo then blue screen then it restarts again can anyone help?This is most likely a conflict of the two operating systems (I think I just stated something we all already know)

Were both operating systems installed on the same hard disk?

And what about Safemode?
(To enter SafeMode, press F8 a few times before Windows starts)
If that works, try the following: Go to Start>Programs>Accessories>System Tools> System Restore
Its self explanatory from that point on hi i've messed about and messed about and now when i try to INSTALL vista it says ''this computer's hardware may not support booting to this disk. ensure that the disk's controller is enabled in the computer's bios menu'' i'm lost i don't know how to change this