k problem goes sumthing like this....

at my home pc i hv a 10 gb harddisk..nd has windows 98 as the OS.
this time i brought home the hard disk of my coll. PC home...this one is 80 gb and has Windows XP..
now can i boot my home PC using my coll.(80 gb win xp) hard disk as the primary harddisk...

If you put it (XP hard disk) in place as the primary boot disk, and the machine bios recognizes the disk properly, it will boot once the system files are found. However, an XP hard disk placed into another machine will trigger the "hardware change tracking" capabilities of XP and it probably won't run.

so basically i cannot boot with my xp disk.. right ???...newaz thnx for the help.. btw is their a way out of this i mean can i change the BIOS settings someway so that the XP hardware tracking system is not activated ..

You would need to at least run a repair install of XP

http://support.microsoft.com/default...;en-us;Q315341

During Activation you would probably have to convince a MS rep that the old computer is toast.

The policy is: one XP = one computer.