Managing Office 2010 Client Key

If you run into any difficulties in activating or uninstalling Office 2010 Key, run this command at "C:\Program Files\Microsoft Office\Office14"

cscript OSPP.VBS

A list of options would be displayed.

If you're planning the sysprep this image, rearm the Office 2010 first:
C:\Program Files\Common Files\Microsoft Shared\OfficeSoftwareProtectionPlatform>ospprearm.exe

After that, check its Client Machine ID is now cleared:
C:\Program Files\Microsoft Office\Office14>cscript ospp.vbs /dcmid

If mails are stuck in draft or Outbox, try restarting the Exchange Mail Submission service on the client access server.