Just follow the procedures listed on this site:
If you were like me and don't have any DRM protected stuff (Windows XP SP2), just do this:
- Go to C:\Documents and Settings\All Users
- Go to Tools -> Folder Options -> View -> Select "Show hidden files and folders" and uncheck "Hide protected operating system files (Recommended)".
- In C:\Documents and Settings\All Users you should see a folder named "DRM"
- Rename DRM to DRMBackup or delete if if you don't care.
- Then visit this website: http://drmlicense.one.microsoft.com/Indivsite/en/indivit.asp
- The site above will repair your DRM instance, then unshare and share your media.