Installing Python 3.6.4, Windows 10 64bit, exits installer and dumps the following error code to log.

[18B8:4394][2018-02-27T15:41:06]i399: Apply complete, result: 0x80070643, restart: None, ba requested restart:  No

0x80070643 - Fatal Error during installation


Attempted Command line installation as Administrator, installation standard methods as Administrator

Make sure all your Windows updates are installed, reboot if necessary, and try again.

I believe this is the error that occurs when another installation is ongoing, and Windows Update is about the only tool likely to be installing something without telling you or us about it. It's a known and ongoing issue right now, but not something we can resolve from our installer.

I am trying to uninstall python 3.7.2 because I think it is preventing me from correctly using python 3.8.2. When I go to my program list on windows 10 and try to uninstall it, it gets approximately 10% in and then gives me the message that No python 3.7 installation was detected. I hit Ok and then it continues loading for another 1% and then I receive the error message "0x80070643 Fatal Error during installation " How do I resolve this?

Your best bet is to repair the Python 3.7.2 install first (through Programs and Features, if possible), and then uninstall it.

Any idea why it's interfering with Python 3.8? That shouldn't be the case (unless it's PATH related, in which case yeah, that's more or less expected).