What free antivirus should i get?

Both those only provide a modicum of protection. MSE misses a huge number of viruses and gets a 0 out of 5 rating. I am routinely asked to disinfect systems with those on a monthly basis. My S-I-L had them and by the time I finished her machine, Bit Defender had routed out 1200+ infected files.

http/www.av-test.org/en/antivirus/home-windows/windows-7/february-2014/microsoft-security-essentials-4.4-140671/
http/www.av-test.org/en/antivirus/home-windows/windows-7/august-2014/microsoft-security-essentials-4.5-143171/

Protection against 0-day malware attacks, inclusive of web and e-mail threats (Real-World Testing)
Detected 77 % / 78% of 194 viruses compared with industry average of 96%

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That equates to missing about 6 times more than the *average* scanner

Detection of widespread and prevalent malware discovered in the last 4 weeks (the AV-TEST reference set)
Detected 77 % / 79% of 194 viruses compared with industry average of 96%

Click to expand...

That equates to missing about 11 times more than the *average* scanner

Bit Defender and at least 5 others scored 100% in both categories and do so routinely. AVG Free scored 98%, Panda free scored 100% (last test)

Free is not always a bargain...... To my mind $10 is a great deal ..... The Geek Squad loves MSE ..... the false sense of security that comes with using it means peeps wind up paying these guys $200 to have a high school kid clean it for you.

http/www.geeksquad.com/services/computers/virus-and-spyware-removal.aspx

Rest assured after a visit to Geek Squad, no one continues to rely on Defender or MSE. I do it for free as a favor to folks, but after I clean a system with BitDefender or one of the other major vendors, they get to use it for 30 days. If they don't license it or another quality vendor's product they are on their own. I won't do it a 2nd time.