Eight days ago I redownloaded Spybot (free version) and performed a scan because I noticed I was getting a lot of strange commercial spam mails.
I removed everything (all cookies and a few reg. changes but no malware apparently) as usual but...

From that moment on, I've been unable to login to several forums I never had a problem with and I found a whole bunch where I can't register either.
It doesn't appear to be a problem with the browsers because this happens with Explorer, Firefox, Chrome as well as Edge.

In all cases, when the login button is pressed nothing happens... but I did notice that websites such as google or youtube or facebook (and even the Microsoft Community where I posted the same question I'm posting here) do work and I can log normally there.

Websites such as www.ilmattino.it (any article where I want to post a comment requires me to login and this is how I basically found out of this problem) or http://www.tgf-clan.com/joomla/ simply do not work and I do not know why.

I suspect this has something to do with Spybot but before uninstalling this program I've been using for so long without problems I thought I'd better ask.

It is just by God's grace it seems that I managed to register here and post the question (these forums look like the same as Garmin forums where I do NOT have the problem).
Do you guys have any clue about what's going on here?