New mother board and processor is installed from PENTIUM -4 to AMD bulldozer 6100.How I can utilize the same hard disk without formatting "C-Drive" which is having os-XP and windows server 2003? please reply.
Windows has a tendency to start barfing all over the place unless the new motherboard is nearly identical to the one it originally got installed on, so I doubt you will have much luck salvaging your OS installs.
The best long-shot I have read about involves removing board-specific drivers before removing the HDD from the previous PC and hope all necessary generic drivers are present and functional enough to allow recovery on the new PC.
I'm afraid you will have to Repair-Reinstall Windows XP... InvalidError has a good idea but I seriously dodubt Windows XP includes all the drivers pertaining to the new motherboard... besides it would probably deactivate.. and even if you don't mind reactivating it, it would be more convenient to Activate it after a repair reinstall which would do a much better job than removing drivers before moving it, and hoping for the best automatic result.