Building, integrating, or customizing apps and workflows within Microsoft Teams using developer tools and APIs
Microsoft teams did NOT uninstall itself. i can also press the "modify" button for teams machine-wide installer WITHOUT that error message popping up.
I think the issue that caused this wasn't that the teams machine wide installer exists, it was that it couldn't find the file in the computer anywhere, but the computer still thought it had it at the same time. this probably caused issues. it might have also been a registry issue as well.
either way, reinstalling windows 10 fixed the problem.
(for anyone wondering how to reinstall windows 10, there are two options.
option 1 is to click on the windows icon at the bottom left, click settings, click update and security, click recovery on the left menu, then you will see an option to reset this pc, press "get started" underneath it.
Option 2 is if you can't get to that; completely turn the computer off, turn it on again, but when you see the first screen that pops up (it is like a boot up screen with loading symbols), hold the power key on the keyboard to force shut off the computer before it leaves that initial screen, then do it again (turn on until boot up screen then force off), then turn on a third time and let it boot up. it will then go to recovery mode where you can look around to find an option to "reset this PC" (that is probably the wording).
After that, your PC will reinstall windows)
for anyone reading this, unless you have a lot of time, are fairly tech sabby, and are very curious, don't bother trying to go a ton of overcomplicated routes. just reset the PC. you will save time in the long run. you you are having problems with stuff not working in general, just reset it after saving whatever files you want.