-  Double click "Fix AutoCAD not open"  windows-update-shield.png icon on your desktop.

-  Once it is completed then open your AutoCAD normally.

NOTE

-  If you don't see that icon on your desktop, follow these steps:

-  Click on the windows logo  Windows_Vista-logo-1A3AAA2064-seeklogo.com.gif  at the bottom of left corner

-  In the search box, type cmd and then hit enter

-  The black window pops up, type gpupdate and then hit enter

-  Once it finishes, you should see the icon  windows-update-shield.png  on your desktop.