I think you know that this is far from likely.
I'd make plans for a clean install.
I have tried to find out the best way to remove WinXP from my dual boot system but I found a lot of opinions and I want to make sure that it will work.
My configuration is this: WinXP on drive C:, primary partition, Vista 32bit on drive D:, logical drive.
Obviously boot configuration is on drive C:. How can I remove WinXP without losing my Vista OS so that afterward I can install Win7?