You may want to try cleaning your machines too.
I've been in the IT business a long time. Lately there has been lot more Malware going around. This crap can run in the background and really suck up resources...as well as do other bad things. I see it on work PCs all the time....and these people don't even have admin rights to install software.
If you need to install a program from the Internet, go to the company's website to get the software. Don't use the mass download sites like Cnet, sourceforge, etc. Sometimes they package extra crap with whatever you download, and you don't always get the option to deselect the extra crap. Also, sometimes the apps themselves are not legitimate.
Some basic stuff that may save you a lot of grief is:
Run
Malwarebytes found at Malwarebytes.org. It's free and won't conflict with existing AV software as it only runs when you do a scan with it. It's been around for a long time and works very well. You just need to run it once in a while to do a scan.
Run
CCleaner found at piriform.com. I've been using this for a long time too. I've never had it mess up a machine. But it offers the ability to do a backup of any changes before it does them so you can revert back if you need to. It deletes left over temp and crap files, and registry keys.
If you use Google Chrome, delete any extensions that you don't use, or don't know. (Look them up before deleting them if you are not sure.) We've been seeing an increase of malicious Chrome extensions lately too. Extensions can run in the background even if you have Chrome shutdown.
And keep all of your programs, Operating System, and drivers up to date.
Anyway, cleaning up your computers may help the game run better.