I have gone back to W7 having fallen out with W8.1. It's a long story, but Win updates kept undoing MY settings and re-installing ITS settings. Now that's not on in my world, so W8.1 has gone - Goodbye and good riddance.
Anyway, about this new kid.......... because I was getting shut of W8 I thought that I would try a few things out, some quite dangerous things, just to see how things went. I was going to do a fresh install so was not bothered about malware or viruses, so risk didn't even factor. What I did was to download some free firewalls and free AV suites, and off I went.
Yes, I got hit, as expected, and I cleaned things up as best I could, and I went on a few blogs to see what others were doing when this was mentioned, so I thought I would pass it on.
I downloaded two apps from the site: the 360 Total Security and the 360 Browser, and was mighty impressed with both. The browser is a Chrome clone with a few extensions built in such as a pop-up and ad blocker, a download manager and two rendering engines which work automatically on different types of web pages. It is blindingly fast.
Then came the security suite. It does not have a firewall, more later, so is not quite "total", but what it does offer is real-time scanning/protection, manual scan, tune-up, junk file finder/remover, sandbox and registry cleaner. When doing a full scan it used about 8% CPU and 45MB of memory - not bad at all, and when it was not scanning but in active mode it didn't register any CPU and only 32MB memory. A full deep scan of a near 800GB disc took 18 minutes.
Now, to be totally protected a firewall is needed. I have been using the Windows Firewall but it is a bit difficult to set up, but if anyone wants to use it Windows Firewall Control will help - it's free. However, there are other firewalls out there and this, Private Firewall is one I found to work the best "out of the box" free one. It used to be a paid product. It is light on resources at 0.4% CPU and 11MB.
I ran Private firewall and 360 Security on W8.1 and W7 for over a week without any problems. I am not saying that anyone should barge in and change things for no reason, but if you feel the need for a change or get sick of having to update/register constantly then 360 and Private Firewall might be worth a bookmark.
One other thing I found is this. Something to sit alongside Malwarebytes.