After upgrading H/W, do i need to reinstall XP?

[MenTaLLyMenTaL]

Hey,
I bought a new proc, mobo, ram to upgrade my old P2. As i'm keeping the old HDD, will it be OK to start the new system with the old HDD as it is with the old WinXP installation? bcoz, XP will be seeing all new core hardware o_O.
Or should I format the HDD on another PC and then connect it to the new setup and install XP again?

[zyberboy]

u should format the hdd and reinstall the OS, also its better to buy new hdd if u hav a vry old hdd otherwise it will slowdown ur new pc.