微软挖的坑，很是烦人。还好老外这篇文章亲测可行。懒得翻译了，权做笔记吧。
网址是：https://jessehouwing.net/visual-studio-2017-force-uninstall/
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:\ProgramData\Microsoft\VisualStudio\15.0
- C:\ProgramData\Microsoft\VisualStudio\Packages
- %appdata%\Microsoft\VisualStudio\15.0*
- %appdata%\Microsoft\VisualStudio\Packages
- C:\Program Files (x86)\Microsoft Visual Studio\2017
- HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\15.0*
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\15.0*
最后，感谢作者：
Jesse Houwing