It had to happen. When Microsoft claimed their next major Windows XP service pack release would not be available to those naughty pirates who downloaded the operating system from alt.binaries.warez.something.or.other they took the opportunity to created a "keygen" to allow them to upgrade.

A keygen is a program that creates serial product keys for specific programs. Very naughty. It also means there is an almost infinite amount of VALID serial numbers created - making it a massive headache for Microsoft.

Windows XP Service Pack 2 is due to land in August this year although a preview candidate is available to download now, if you so wish. Personally, I would wait until it's final.