then the problem may be with you hardware,
how many memory stick you hooked with you motherboard,,
try installation with only one ram stick..
I have 4 slots of memory on the MOBO, I have 2 stick of 2G memory total of 4G.
Win7 works perfectly with 4 G. of memory, and that XP will not work with 4G. I'll try, but it does not make sense that when I want to dual boot with XP I have to remove a memory stick. tia