My 18.0 became unusable after removing and then reinstalling 18.1. I get a com init error.

I then uninstalled 18.0 and did a re-install. I didn't have my reg codes available, so at the end of the install, it got in a loop of two popups telling me my demo was past date. I had to kill the process to get out of the loop. Leaving early, 18.0 did not register with Windows as an app. I can not uninstall 18.0 so I can install with my codes, getting an already installed error.

Windows 8.1

All has been working great until now. Had to try a big download with my new internet provider so picked 18.1 and did a reinstall. Oops

I have registered 18.0 with its program, so it now seems to be working. Except I can not pre-compile the system packages do to rights, even though I'm running as administrator.

I'm not sure how to handle things when I need to delete 18.0 from the computer. I would like to do that now so I can get a clean install.