Eset's NOD32 is not a free program, but is inexpensive ($27 annual renewal), and protects against viruses and spy/malware. It has a very small footprint, and It has won more awards, and has a better detection/removal rate that any of the above listed programs including Symantec's Norton, and Mcafee. Microsoft is a client of theirs and use it to protect their own servers.
"VB100 AWARD The VB100 award was first introduced in 1998. In order to display the VB100 logo, an anti-virus product must have demonstrated in our tests that: The product must fulfil these critera in its default state." Test results Kaspersky: 42 Success / 16 Failure / 0 No Entry
Norton: 44 Success / 6 Failure / 8 No Entry
Mcafee: 35 Success / 20 Failure / 3 No Entry
Avast: 25 Success / 22 Failure / 11 No Entry (
failed sp1 Vista)
AVG: 22 Success / 22 Failure / 14 No Entry
Bullguard: 3 Success / 1 Failure / 54 No Entry (
failed sp1 Vista)
Eset NOD32: 50 Success / 3 Failure / 5 No Entry
https://www.virusbtn.com/Session-fc676352874782cebf17fc269f75f3a3/vb100/archive/results?vendor=VE14
Vendor Test History
https://www.virusbtn.com/Session-fc6...isplay=vendors