I closed Revo down and restarted the computer. After the reboot I didn't find any traces of Ad-Aware on the computer, plus I'm not getting the error message anymore. So it looks like it worked.
I'm actually having the exact same problem as synthiat. I tried Revo to uninstall and it seems to have work... I think. I followed the instructions to remove Ad-Aware using Revo, and the 1814 error seems to have gone away. But, there's a part where you have to check the bolded files to remove any leftover registry files. I deleted the files but Revo doesn't give me the option to advance after that. I can only click Cancel or Back, but not Next. Is that something I should be worried about?