OMG. I'm still shaking. Once the remote "John" had installed RegServo he/she tried to hard-sell me on other programs. I declined politely several times until I finally typed, "Thank you for your help. Have a nice evening."... at which point I tried to end the remote conversation.
That's when the bizarre ensued. It became a battle with my cursor - I would try to 'X' out of the conversation and he would take over and scroll around, highlighting parts of the conversation. This went on for some time as I was as scared as if someone had broken into my home.
I made it to the Windows icon to shut down but he hit 'cancel.' I ended up just holding down the shut down button, which worked, but when I powered up again after a while, the chat screen was still there. I made it to that to 'X' out of before he noticed, I guess, but I wonder what damage has been done. I uninstalled the program, but who knows.
I've used remote help in the past, but nothing like this has ever happened. I will never use it again.