Sorry to have so many posts to explain my problem, but I just now got back to this. I rebooted the thing and it booted up into Safe mode just fine. Not sure where to go next, but I just ran rkill again and am doing a MalwareBytes scan now.
Full story: Last night I went through the prcedure outlined at http://www.bleepingcomputer.com/virus-removal/remove-antivirus-action
and got along fine until it was time to deal with the HOSTS file. I downloaded hosts-perm.bat and ran it (at least I thought I did.) Then I went to search for the file that is supposed to be at C:\Windows\System32\Drivers\etc\HOSTS
Well, imagine my amazement when there WAS NO WINDOWS FOLDER showing on C drive! This was so weird that I really had no idea what to do. After puttering awhile, I did find two files like that in the WINNT file, and I deleted those. (Thought process: We don't use NT anyway, so it shouldn't hurt, even if it doesn't help. Right or no?)
So then I tried to go ahead and run the replacement HOSTS file, which wouldn't open. It just gave me a window asking what I'd like to open it with. (I had to download it on this computer and take it to that one on a flashdrive, since that one wouldn't access the Internet anymore--would that make a difference?) Having no idea what to do next, I went to bed. Awakened to this weird DOS screen saying there was no hard drive or OS. Thankfully, that is no longer happening, but does anyone have a tip as to why I seem to have no Windows folder, when I get to that point again?