Thread title should read, "Installing a program on both OSX and on Windows (Parallels)." Is there any problem if you install a program on both Mac OSx and on Windows (through Parallels)? In particular, I plan to install Quicken 2015 Windows even though I already have Quicken Mac 2015 installed. I plan to migrate over to Quicken 2015 Windows but will want to run both programs for a time (to verify that the transactions match).