finding it was the hard part. First, do file->export registry value when the key is selected. then call the file something you can remember. change the value to 1.3.1, reboot and try to install. if that doesn't work try 1.3 and retry the install. If you get it to install, double click on the .reg file you made and reinstall your old value. I would also reload your old value if you can't get it to work at all. I think this is all you can do without installing the old version. If this doesn't work, repost your question in this thread and I'll see if I can't figure something else out for you. Best of luck.