I had to uninstall Postman on a Windows 10 Pro 64-bit machine, and when I try to reinstall it, I get the following error message:
Version mismatch detected. Looks like you’ve used a newer version of the Postman app on this system. Please download the latest app and try again.
So it seems as if the app auto-updated to a version that’s newer than the one available for download, and that somehow makes it impossible to reinstall.