The other one I can not log into to try.

Windows Defender does NOT get it all. It's one of the worst antivirus and antimalware out there.

What do you use or suggest?
I currently use Windows Defender.

Spybot Search and Destory is a good antimalware also.

For antivirus, Bitdefender is well rated, among others.

As I said before, I can't even log into the laptop. The PC I can log into, but it will not take any keyboard commands. The mouse still works on both machines.

The thing to do is to boot up into a rescue antivirus/antimalware mode and scan your hard drives thoroughly.

http://www.avira.com/en/download/product/avira-rescue-system

Download the iso file and burn it directly to a CD or DVD if you can. Then, boot up off the CD or DVD and scan the hard drives. Boot directly into the rescue mode, do not boot up into Windows. You have to carefully watch your bootup to make sure you do this.

You can also use a USB thumb drive, Rufus

You probably have to keep tapping F12 key or something like that to make sure you boot up the CD or DVD first. You can also go into your BIOS via the Delete key (probably) and change your settings to make sure your CD or DVD drive boots up FIRST instead of your regular hard drive.

If this doesn't work for some reason, you have two options left: 1) Take it to a qualified repair shop locally or 2) a gamble, erasing your hard drives AFTER saving all your data and reinstalling Windows 8.1. As I said, option 2 is a gamble, because it might be a hardware (motherboard? - pretty unlikely to have mobo problems on TWO computers at the same time but it's theoretically possible I guess) problem. Personally to be safe, if the antivirus scan doesn't work, I'd take them to a repair shop. Good luck.

but just recently I had a problem w/my laptop. It would boot up, but the screen was black and the keyboard wouldn't work. Attaching a vga cord, I realized I could see the desktop on my tv.

I found the correct keyboard model, ordered it, installed it and my problem went away.