[via vowe]

I haven’t tested this, but it seems to be interesting. If you have a *dynamic* WinXP installation – i.e if you are instaling/uninstalling/testing a lot of softwares and tools, you surely have already re-installed your machine, because of the performance.

It seems that there is a way to avoid the re-activation process after your re-installation, by backup-ing a small file called WPA.DBL (in \windows\system32\) and by replacing this file after the re-install.

Have a look at the full article.