I deleted a Firefox profile while troubleshooting a selenium/geckodriver issue. Doing so deleted many unrelated folders and files, but long story short my Python folder was obliterated but for a single file called vcruntime140_1.dll. It also rendered Firefox unusable. I reinstalled Firefox with no success. I tried the refresh option from the installer instead — no success. I deleted everything I could find in regedit and my C: drive (no clue why several folders are left behind after uninstalling...). Re-install still failed: during all attempts I could open a Firefox window but I couldn't do anything within. On a hunch I went into my recycling bin and restored the vcruntime140_1.dll that I had deleted, and Firefox started working again. I moved it from my Python folder (cause surely it doesn't belong there, apparently it's a Microsoft file) and Firefox stopped working... I want to know where this .dll actually belongs, and if possible I would like to know a way to obliterate Firefox from my PC. Uninstalling should accomplish that, but sadly does not. Any other advice/commentary is welcome.