There is a ton of freeware on the internet ready to be downloaded and used if you look for it. I'm going to share some today that deserve a look.
I believe MBytes is the best free malware (programs designed with malicious intent) removal tool today. I use it at home and even at work, if needed. It's easy to use, accomplishes the job, and hey, it's free.
Every computer needs real-time virus protection, some would disagree, though their reasoning for disagreement hasn't suaded me. AVG Free provides adequate real-time protection for your computer. Just like MBytes, it has an easy to understand interface with large descriptive icons. Now, I have to be honest, AVG has fallen behind a bit on being the "best" virus protection out there. However, combined with MalwareBytes and Superanti-Spyware, you have a good trio of protection against those nasty viruses.
This is one of the best free tools for getting rid of spyware. What is spyware? Spyware tracks your internet usuage to create a marketing profile that is then sold to companies; this is without your consent too. Also, spyware can burden your computer's performance. With SuperAnti-Spyware you can eliminate the rogues from your computer.
These three free (did I mention they're free?) security tools, when combined, prove to be a colossus of protection for you and your computer. If you aren't currently using any security tools, I suggest you download these now before it's too late. They are lightweight, powerful, and easy to use. Run AVG scans everyday at a time when you won't be on your computer, and run the other two at least once a week. You won't regret it.