You missed the best in Poll buddy!
1. Avira Anvivir - http://www.free-av.com/en/download/index.html
Avira is best & light solution for excellent overall system protection & internet security with real time updates, .
2. Malwarebytes - http://www.malwarebytes.org/
Malwarebytes is one of the best & effective antimalware tool out there.
3. Ccleaner - http://www.piriform.com/ccleaner/download
CCleaner is a system optimization, privacy and cleaning tool with an effecient & most useful registry cleaner.
The Best Security combo for all types of systems.