As long as I can remember Python requires administrator rights on Windows for normal installation.

I have the same problem.

Even if I install it with the administrator privileges, it still cannot be installed successfully.

Python 3.13.4 (64-bit)_20250608181724.log

Then I changed the installation path to d:\devtools\python

Sometimes it happens：

As long as I can remember Python requires administrator rights on Windows for normal installation.

Hasn't been required since 3.5 - it was one of the first things I fixed over ten years ago.

Sometimes it happens：

This seems like some pretty significant system corruption. You might be heading towards needing to do an OS reset to clean up whatever things have gotten messed up over time.

I don't usually try the upgrade option instead, but I tried it just now because I didn't want to have to reinstall my libraries, and the installer simply deleted all the main Python files from the current Python directory, leaving me with no working installation of Python.

This tends to happen after you've done non-standard installs previously (such as installing a new version on top of an old one without uninstalling the earlier one). The installers work fine when you follow the defaults, and almost always work fine if you choose your directories carefully (without collisions/overwriting), but break down very quickly if you do anything weirder than that. It's a big part of why we've deprecated them and are moving towards a system where you don't even get that choice (and if you want that choice, you'll clearly take full responsibility for it so there's no installer involved to break).

If you install pip as part of it, you usually need to Repair before you Uninstall, or else pip's uninstallation breaks. If you've got old installs registered, even if the files are not actually present, then I'd suggest going through each and repairing then uninstalling them one at a time. By the end, you should be clear enough to install the version you want.

Or alternatively, you might switch to the new installer and install all the old versions you want with that. You've clearly got some strong preferences for some reason, so I'd be interested to hear how badly the new installer breaks your workflow and why, to see if there's any way we can support it.

@zooba Oh, if you're talking to me, I don't have any particular preference for installer, I just want to use what's best. The installer I used was the most obvious/default link to the latest version that I found near the top of the front page of python.org. Thanks for all the info.