I'm not sure exactly what happen the Windows Media Player is no longer can be opened after I created a new user account in my Windows Vista system. When using the original user account of my Vista machine, it still works fine. It is just that it doesn't work for the new user account that I created.
When I double-click the Windows Media Player, nothing comes out. When I double-click the videos and movies, it usually plays automatically with Windows Media Player but it just nothing happens. At first, I was thinking to reformat my whole drive and reinstall the windows but WAIT... Luckily, I found a solution to that.
To fix that, you need to perform the following steps:
(1) Open “Command Prompt” in Administrator Mode.
(2) Run “regsvr32 jscript.dll”
After the command, you will see the “DllRegisterServer in jscript.dll succeed” dialogue box. Now, you can open your windows media player! :) Hope this helps and works for you too!