Computer in odd state, can't get out of it

Hi,

When I installed Parallels, my computer had a boot camp partition that I hadn't used in a while. Parallels showed it, so I tried to start it.

Parallels said it had to convert the volume to work, then tried to boot it, and the boot failed, leaving me with a dead window. I quit Parallels and restarted my computer, but my computer booted to a black screen with a blinking cursor. I rebooted again with the Option key held down and got MacOS to start. I then used Disk Utility to remove the Boot Camp partition.

I restarted Parallels, intending to do a fresh install of Windows, but Parallels instead immediately went back to a screen claiming it was upgrading my Boot Camp partition. I had to force-quit to exit out of it. I then uninstalled Parallels, rebooted my computer, and did a disk repair of both my disk and my primary MacOS volume just to be safe. I then reinstalled Parallels. But when I ran it, it went right back to the screen trying to upgrade my (nonexistent) Boot Camp partition.

Now I can't get Parallels to do anything else, even after several uninstalls and reinstalls.

I also noticed that Boot Camp Assistant will no longer start on my computer. Or rather, it starts but fails to show any window.

I don't know what to do next. I'd like to use Parallels, but I can't get it to forget about Boot Camp and do anything new.

Frank