Thanks for answering my questions.
RP's: I did follow your instructions, but actually I had to execute Step 2 twice, because the first time the computer looked like doing nothing (just like it happened while executing the previous set of instructions). So afer restarting the computer, I repeated Step 2, which worked fine this time; then went on to Step 3, which removed OTL. (I didn't report it as I thought it wasn't an issue). Maybe the repetition caused the removal of the new restore point?
Anyhow, I have created a RP now directly from System Restore as per your latest instruction.
Your answers are all clear.
Just one further point on the firewall: I will "study" the Online Armor Firewall to understand how it works before installing it. If I have any questions on this, what's the most appropriate place where to ask them: a forum on this website or somewhere else?