WMP DRM security update problem

I am trying to update my DRM security
(http://drmlicense.one.microsoft.com/Indivsite/en/indivit.asp). Whenever I
click the 'update' button, the browser freezes.

I am using WMP 11. Windows XP SP3. It sounds like the problem described in
KB925507 - but surely SP3 should have solved that. I downloaded the hotfix.
It encluded the files 'riprep' and 'sysrep' and i have no idea what to do
with it.

Any ideas how i can install this update or how to apply the hotfix?