Free Antivirus Programs
If you do have a virus or malware problem with a computer, a simple, effective solution is Avast. It has been one of the top rated, free antivirus programs for years.
I had been using AVG for years, but one day I noticed a problem. I often keep my small 'local area connection status' window open. I noticed something was downloading when nothing should be. When I couldn't find out what was happening, I disconnected the internet access line.
I wanted to do a virus scan with AVG but couldn't. AVG and Windows Defender had both been disabled, and weren't working. This was not because of anything I had done. I obviously had a serious problem.
I hooked up my internet connection just long enough to download Avast. When I started it, one of the options was a 'boot time scan.' I selected that. It restarted the computer and half way through the restart, it stopped everything and did its scan.
It found 4 files that it didn't like and I chose to delete them. It was a downloader Trojan and I Googled it. The results were stories of computers that could not be used after it was finished with them. Its way of operating was to disable computer protection, and then download one bit of malware after another and put them all to work. I was very fortunate to have caught it early enough to stop it.
That was the only serious problem I had, and it was a lot of years ago, but Avast has been handy since then. Not long ago a neighbor had problems with his computer. He is an old timer who is not very computer savvy. He was helping on a volunteer project that I work for, and I was happy to help him out.
When I looked at his computer, both AVG and Windows Defender were disabled and wouldn't even open. He complained about pop up ads and his browser being redirected. When I tried to download Avast, the browser was redirected to a fake Avast site. It is surprising how complete some of these attack systems are.
I went home and downloaded a copy of Firefox to a USB key. Started his computer again and downloaded Avast using Firefox from the USB key. That worked. I installed Avast and when it started I selected the boot time scan option, and clicked restart. The whole computer froze.
Finally I had to turn it off with the button. When I started it again, Avast started its scan. It found 10 files that it identified as malware, and it was a pleasure to delete them.
Avast has mentioned that it finds some root kits during these boot time scans. That is more than most antivirus programs can do.
I started his disk defragment program for him. It had never been done on the computer.
The next time I saw him, he said the computer was running much better.
Isn't this sort of stuff much more interesting than watching TV?
So out of the 3 systems I have used, I have to rate Avast the best. Second goes to Microsoft Security Essentials. MS has been keeping a catalog of malware since the internet started. This program was a bit clunky when it was first released, but it got smoother and better for the 18 months I was using it. Third is AVG.