https
/www.av-test.org/en/antivirus/home-windows/
KA Scores 5.0 -5.0 - 5.0
http
/usa.kaspersky.com/downloads/
BD Scores 4.5 - 5.0 - 4.5
http
/www.bitdefender.com/Downloads/
AVG Scores 5.0 - 4.5 - 5.0
http/www.avg.com/us-en/free-antivirus-download
TrendMicro Scores 4.5 - 5.0 - 5.0
http/www.trendmicro.com/us/security/products/index.html
I would suggest never buying directly from the AV vendors.... you can usually get any of the above total solutions for about $10 per seat.
If you want to see how the free versions compare with the paid for versions, ;look at the avtest link above.
Avast Free caught 100.0 - 97.3 - 99.8 and 99.9 in the last test
https
/www.av-test.org/en/antivirus/home-windows/windows-8/june-2016/avast-free-antivirus-2016-162213/
Panda Free caught 97.8 - 98.6 - 99.7 - 99.8 in the last test
https
/www.av-test.org/en/antivirus/home-windows/windows-8/june-2016/panda-security-free-antivirus-16.1-162286/
Windows defender wasn't tested last round ... even tho last test did show big improvement, missing 10% of 0-day malware attacks is scary
Dec 15 (4.5 / 6.0 rating) = 97.5 -
90.0 - 99.6 - 99.6
https
/www.av-test.org/en/antivirus/home-windows/windows-8/december-2015/microsoft-windows-defender-4.8-154547/
June 2015 (0.5 / 6.0 rating) =
90.2 - 84.7 - 88.5 - 95.2
https
/www.av-test.org/en/antivirus/home-windows/windows-8/june-2015/microsoft-windows-defender-4.7-152347/
Feb 2015 (0.0 / 6.0 rating) =
69.3 - 76.6 - 73.8 - 73.7
https
/www.av-test.org/en/antivirus/home-windows/windows-8/february-2015/microsoft-windows-defender-4.6-150671/
Both also did rather poorly in the performance test
They don't even list defender any more