Hi Margaret. Each version of PSP is installed independently. I have no less than 14 versions installed, and I often have 2 or 3 versions RUNNING at the same time. The only time you have to uninstall before reinstalling is if you have downloaded a TRIAL, and purchased it after, because the trial version typically only includes the 64-bit version, while you need to download a “full” version to include the 32-bit too. As far as I know, it is the only situation where you would have to uninstall first.