No it is a bad idea but may be possible in some cases.
You will have to check at Avast forums but Im pretty sure that if you install Avast after AVG it will not install any resident parts - to avoid what SIW2 said. And it should/could work with 2 AVs. Depends on which I guess and you must check before experimenting.
Other products like Trend, Mcafee wont even install if they detect competing stuff, even goes for Spybot&Destroy. Generally no AV is compatible with other AV - go to site of AV, look up "compatibility".
Dont forget you also have Windows Defender running, I think a lot better than both AVG and Avast when it comes to blocking certain types of infections. 100% compatible with at least free Avira and Avast, would think AVG as well. Not always the case with paid AV - becomes a competing product then, or whatever technical reason is valid
You can install all you like but look out for what is actually running - S&Ds stuff is somewhat troublesome
Petition to remove TeaTimer from default installation. - Safer Networking ForumsJust untick during install or do it later. No problem.
There are many online scanners if you want a 2nd oppinion so not much need to have more than 1 AV installed.
Also consider using site like VirusTotal which let 39 AV programs test 1 file you upload - get handy little SendTo uploader here
VirusTotal - Free Online Virus and Malware Scan - Email/Uploader - works on 64bit.
And use services like OpenDNS, Firefox for blocking sites to avoid installations. May be also WOT for Firefox/IE
Internet Security | WOT Web of TrustWOT is pretty quick in detecting new malware domains, faster than OpenDNS, Google, Avira, Norton, Mcafee from my brief test using LinkExtend
https://addons.mozilla.org/en-US/firefox/addon/10777 Test your self, easy to find a site with bad domains. WOT seem to have most and go "HIGH RISK" where the others say "UNKNOWN".
Is a little scary that fairly old bad domains dont get blocked faster by those who are paid to focus on such things. Just shows you should not rely on 1 product/service no matter name.
