If you, like me, are stuck trying to upgrade Visual Studio 2017, then you may only get unblocked by removing everything and starting afresh. Since Visual Studio 2017 is still in Release Candidate and not final, this is something we may have to deal with from time to time.
But when the "uninstall" button in the ui fails, you may end up stuck. In that case, you'll be happy to find:
C:\Program Files (x86)\Microsoft Visual Studio\Installer\resources\app\layout\installcleanup.exe
Which will perform the same actions as the good old "vssetup.exe /uninstall /force". If that doesn't get you unstuck, there is an even more forceful way:
Delete everything under:
- C:\Program Files (x86)\Microsoft Visual Studio\2017