I am planning on upgrading my CPU soon. I currently have a MSI NeoF MB with a P4 3.4 (500 series) CPU running XP Home. I am planning on upgrading the CPU to a Core 2 Duo CPU (the mb will take socket 775 cpu's w/ 800 or 1066 fsb).

My question is if I change just the cpu (from a p4 3.4 to a E6600) will I have to reinstall Windows XP? I have heard differing views on this. Any suggestions would be greatly appreciated.

MSI NeoF mb, P4 3.4 (500 series), 2g OCZ DDR2 5300 ram, 160g WD SATA HD, XFX 8800GTS 320

Generally speaking no you do not have to do anything special. Since you are only switching the cpu rather than the mother board you should be fine. If you were swapping the motherboard or going over to an AMD based mobo and cpu then yes you would need to reload XP a certain way.

Thanks for the info!

I believe your P4 is single core and the E6600 is dual core. The HAL needs to be changed or the system will only see one core.

If you switch the cores it does not matter, XP home and pro will both recognize multiple cpu's weather it is actual cpu's or dual core cpu's. When you switch the cpu the bios will update it's info with the new cpu info and upon reboot the system will start using the 2 cores. I switched a buddies single core p4 with a dual core and it worked fine, no reloaded needed. If for some reason you did need to reload the OS, just do a repair and it will make the changes for the hardware differences.

with changing the cpu you shouldnt have to reinstall windows.