In the course of troubleshooting RMS from the client side it may be beneficial to "start fresh." One may reset the registry and move/delete existing .drm files. The steps are as follows.
  1. Exit running Office applications.
  2. Delete existing registry entries.
  3. Clear existing licenses, GICs (RACs), and etc.
  4. Reproduce the issue.

NOTE: Feel free to export the DRM registry key before deleting it. Moving the *.drm files to another directory may be done instead of deleting them.

Delete the RMS registry settings for the user. 

  1. Open regedit.exe.
  2. Navigate to HKCU\Software\Microsoft\Office\XXX\Common\DRM.
    XXX is the current Office version. 14.0 is Office 2010. There may be multiple versions listed (which is normal). Picking the highest is usually the correct one. 
  3. Delete the CachedCorpLicenseServer value and the LicenseServers and ServiceLocations keys.


Clear the existing licenses, GICs (RACs), and etc. 

  1. Open an elevated command prompt.
  2. Navigate to the apporproate DRM folder location.
    Vista/Windows 7: C:\Users\[username]\AppData\Local\Microsoft\DRM (on these OS versions run "cd %localappdata%\Microsoft\DRM")
    Windows XP/2003: C:\Documents and Settings\[username]\Local Settings\Application Data\Microsoft\DRM 
  3. Move/delete the *.drm files.

NOTE: If you are using the Rights Management Client 2.0 (AKA MSIPC) you may also need to delete the cache in
%LOCALAPPDATA%\Microsoft\MSIPC