You’ll have an mmc on the desktop or a shortcut to AD where you RUN AS and get the “The directory name is invalid”.

Here is a fix for the AD shortcut issue

http://support.microsoft.com/kb/832434

Right click on the AD shortcut in properties and in the Start In put

%windir%

Fix for the MMC is to give the RUNAS user account permissions to the location of the MMC. If it’s on your desktop, then give permissions there. Not just to the icon, but the whole desktop folder or even the whole profile folder.

The message basically means that RUNAS user doesn’t have permissions to that location. Shit error message but that’s what it means.