Your solution worked perfectly for my situation. Just for posterior sake, for those who might be attempting the same thing I did I offer the following information:
I created a RAM-Disk (makes some of the RAM look like a hard drive, ikn my case I made it the "R" drive) to allow my CAD program to run faster. It was taking as much as 5 minutes to complete a "Redraw". I installed the program on the "R" drive instead of
the regular "C" drive, and after a couple of tweeks, all worked well. Except that Win7 wouldn't allow me to set/change the default program for the file type to the program on the "R" drive instead of being in the "C:\Program Files (x86)". I found the Registry
entry following your instructions, and discovered that it was pointing to the "C" drive, despite having told the program installer to install on my "R" drive. Looks like the installer defaults to the "C" drive no matter what you request, when it comes to
the registry entries.
Now that the associations are corrected I find that I can load, redraw, render, and any other task desired with this program in mere seconds (the redraw that used to take 5 minutes, now takes less than 2 seconds).
Thanks again for your solution.
Steve J