Like anything else, shop around and do a comparison check not just on price but quality as well.
There are free programs which will do it all if couple with commonsense when browsing.
I use windows firewall - AVAst free antivirus antimalware
backed up with a scan with malwarebytes free and ADwcleaner
spywareBlaster as a blocker of malicious sites- Adblock pro and ghostery to block scripts and ads when browsing.