There are no "perfect" anti-virus software regardless of how much you pay. "Avast" and "Avira" have one of the highest "detection rates"; better than Norton. You also need to remember that a particular company known for its anti-virus function may not have a good firewall function in its Internet Security Suite, for example. And, what happened with "Avast! Internet Security" may happen to any other Internet Security Suites, because there are no perfect security software. Here is my recommendation:
❶ Install on the three below in concurrent with "Malwarebytes' Anti-Malware Free Edition" (MBAM):
▪ Avira AntiVir Personal (Free Antivirus): http://www.avira.com/en/avira-free-antivirus
▪ Avast! Free Antivirus 6: http://www.avast.com/en-au/free-antivirus-download
▪ Microsoft Security Essentials (MSE): http://www.microsoft.com/security_essentials/
Once you run a scan with one of the three you had decided to install, run a scan with MBAM afterwards, which will allow you to improve the detection rate.
❷ Along with step 1, use password management software, such as "StickPassword" to store all your online backing information, such as your account number and passwords. This software will keep everything encrypted and you just enter your "master password", which will automatically fill in the password and sign you in.
❸ If you want to purchase an "Internet Security Suite", these are very popular:
▪ ESET Smart Security 4
▪ Avira Premium Security Suite
▪ Norton Internet Security 2011
▪ Kspersky Internet Security 2011
Useful links:
▪ Read my answer in this link: https://answersrip.com/question/index?qid=20110430142936AA8HDUK Read through everything. I said to avoid spending money on Internet Security Suites, because I have several computers at home and haven't had a single virus. If you have kids (who are not aware of surfing the Web safely) and/or an Internet Security Suite really gives you that piece of mind, then you should totally go for it.
▪ http://www.av-comparatives.org/en/comparativesreviews/detection-test
▪ http://www.av-test.org/
▪ http://www.virusbtn.com/vb100/index
▪ http://internet-security-suite-review.toptenreviews.com/
▬▬ Edit ▬▬
Go with anything in step 3 along with step 2. You should still run a scan with "Malwarebytes' Anti-Malware Free Edition" after you run a regular scan with your Internet Security Suite.