We use Webroot. We also use Malwarebytes and CCleaner. DH mentioned AVG (which we used before on the old computer) and Avast. Between AVG and Avast, which one is better? And can they both, or either, be used along with Webroot?...
Which Webroot product are you using? If it has an antivirus component, then you should not install another. You should have only 1 antivirus product installed that has on-access protection. The same for anti-malware programs. I like Avira for free AV. I have also heard good things about Panda Cloud. Avira consistently has great detection rates.
Webroot is not that great. If you want a "free" A-V, AVG is OK, but their 8.0 and later packages are loaded with extra crap, and I found that it slows down every system I've had it on. Uninstall it and every thing goes back to normal. I've not insalled AVG, nor recommended it for anyone I have done work for. I switched to avast, then tried Avira (on the laptop only), and now am using MSE (Microsoft Security Essentials) on all of the machines my home network except my own tower, simply because I haven't gotten around to it yet, and the file server (running Linux for now). If you want a "pay" A-V, go with Eset (NOD32) or Kapersky. If you have the coin, buck up for the pay version of Malwarebytes. That'll get you auto updates and real-time protection. The free version is all manual (updates/scans).
Free isnt free with any of those software packages. The only one I know of that is free is Microsofts Security Essentials. Webroot, Avast, Malware Bytes...etc. You have to buy the software to get a good working copy. I am just saying.
If it's free, chances are it won't do the job well. You get what you pay for! I have Kapersky. I was hesitant because I had never heard of it, but it has been great so far!
Amen Silstah....Kaspersky is in the top three and have a wonderful reputation. You do get what you pay for. Microsoft Security Essentials is a wonderful free tool. It's AV, Malware, and any other type of bug.