I had the problem where uninstalling from Control Panel's Program Files (regular or safe mode), or using CCleaner as an intermediate would do nothing after clicking Uninstall. Nothing was ever running in task manager to delete (probably because I'd somehow
managed to remove part of it but not all and was left with a bad state). Then I tried the Fixit program mentioned above and it couldn't find "Chromium". CCleaner found some of the Chromium registry stuff, but the program still lived in some level in Program
Files.
The way I was able to finally get rid of it was like above in the C: > Users >{Personal Named folder} >AppData> Local (I'm also on Windows 10). But with a catch; I'd already previously deleted the "Chromium" folder,
but it was either there or somewhere near that I also found two folders with GUIDs for folder names, also installed on the same date that something gave me Chromium. I deleted those two folders and then was able to finally uninstall Chromium (or more accurately,
went to uninstall from Program Files and it finally responded to click, saying that the program was no longer there).