Ok I got Microsoft Security Essentials. Do I also need Malwarebytes?Welcome
Brink has suggested great anti virus, anti malware software. There is other software, however. My personal choice is the free Microsoft Security Essentials and the Free Malwarebytes for free scanning back up for malware
Malwarebytes : Free Anti-Malware
Microsoft Security Essentials - Microsoft Windows
One feature of Security Essentials that cannot be claimed by Avast is that Security Essentials is made only for Windows, unlike Avast, one size fits all. Good luck. Whichever you choose you will be happy with the results.