IndivBox.key will be downloaded from microsoft server at the first time you try to play DRM protected media. Or if it is already downloaded before, then you should delete the DRM folder ( C:\Documents and Settings\All Users\DRM ), 'coz IndivBox.key needs to be downloaded again.

It depends on what version of media player you use, but not actually version of media player. It will detect runtime file in your system, if you have clean install of Windows XP and never update/upgrade your media player and never applied media player's hotfixes, it will download IndivBox.key v10.00.00.3646 to your C:\Documents and Settings\All Users\DRM

By default, clean install of Windows XP will install windows media player 9, then when you attempt to play drm file for the first time, media player will ask you for a security upgrade.

After you have finished a security upgrade and IndivBox.key has been downloaded to your drm folder, please check what version of your IndivBox.key.


How to individualize your system for the first time?
1. Delete the DRM folder C:\Documents and Settings\All Users\DRM

2. Go to:
http://services.wmdrm.windowsmedia.com/indivSite
and click upgrade.

If your IndivBox.key version is 10.00.00.3646, you will able to un-DRM your medias. And if your version is 10.00.003930, just say good bye to undrm.