Michael said:
If you need to re-install XP is it necessary to activate
again and how is that done?
If you do so fully, reformatting the HD, then you are back at square
one, and need to activate again, which you do exactly as on the first
occasion. Within 30 days, get on the net, go to
Start - All Programs - Accessories - System Tools - Activate Windows
and Activate on the Internet - takes 20 seconds or so.
You can do it as many times as you like on the same (or substantially
the same) hardware. See
www.aumha.org/win5/a/wpa.htm
One exception is systems provided ready installed by the OEM maker;
these are often handled by 'locking to BIOS' instead of through
activation, so you simply use their means of restoring to ex-factory
state