Nov 26, 2007
My friend wants me to swap out his Pentium D processor for a core 2 duo. This is not a question of compatibility because I was the original one who built his system and purposely chose a mobo that gave him the option to upgrade to a core 2 duo in the future. Well the time has come but now I am confused about something. I installed a copy of windows xp professional and in that computer and am wondering if I will need to reinstall windows or just re-activate it? Will windows make me re-enter a password? Will I have to call Microsoft to re-activate it?

For a CPU switch? It will be just fine. The only single part that requires re-activation is the motherboard.

It's possible to initiate a reactivation if you change enough of the older parts....

I don't have the exact figures to hand, but think of it this way. You have to change 45% of your hardware to initiate a re-activation. MS weights your MB as 45%. The rest of your hardware is collectively 55%.