I can’t open *.dwg files through Windows Explorer (Windows 7) (“there was a problem sending the command to the program”). Also, when I right click a drawing file in Windows, open with… ACAD icon is shown as “not applicable”. I am completely frozen up at this time, and the desktop icon will no longer open either.o set the “AutoCAD DWG Launcher” as the default program for DWG files: 1  Locate a DWG file in Windows Explorer. 2  Right-click on the DWG file and select Properties.