guys i have already have win 7 as my O.S...but when i insert my xp cd into my drive it doesnt boot...wat is the problem???...i also chked the xp cd on my bro's pc(which has XP as O.S.).it got booted on his system...helppp
You'll have set the cddrive as the 1st boot to install XP.
-- If you are overwriting W7, quick format the partition that has W7 and install XP there.
-- If you are going for a dual boot system, create a primary partition or use a fresh HDD to install XP. After XP installation, you can boot to your W7 media (CD/USB stick) and perform a repair install to create the bootmanager that allows you select either W7 or XP after POST.