I just upgraded to AutoCAD 2010. Now when I double click a file it wants to open .dwg files with "AutoCAD DWG Launcher", which looks like it is opening in Inventor by the way. I try to change what program opens it to ACAD.EXE in the AutoCAD 2010 folder. When I double click on the ACAD.EXE, the window closes and I go back to the "Open With" dialog box, except, AutoCAD is still not listed as a program to open AutoCAD files with. Any suggestions?