I have a Dell Optiplex 390 running Windows 7. I stream music and video on it quite a bit and this morning when I try to open ANY program, I get an error saying "This file does not have a program associated with it for performing this action. Please install a program, or if one is already installed, create an association in the Default Programs control panel. I have downloaded this exe association registry fix from Microsoft, but cannot get the program to run it. Cannot open command prompt even from Task Manger>New Task. Same symptoms in Safe mode with networking. Any help would be greatly appreciated.