Make sure you are the an administrator
For the registering to work, you must run the command prompt as an administrator or log in to vista as an administrator. Go to accessories, right-click command prompt, and click run as administrator.
1. type regsvr32 jscript.dll and then press enter. you should get a confirmation message.
2. repeat and type regsvr32 vbscript.dll and then press enter.
3. type exit and press enter.
Your error with WMP 11 should now be fixed.