AVG is pretty ineffective actually.
Try Avira whch competes pretty well against even the best paid antivirus software.
Here are the results from AV Comparatives Main Tests
Total detection rates:
1. G DATA – 99.9%
2. Trustport, AVIRA – 99.8%
3. McAfee – 99.4%
4. Avast, Bitdefender – 99.3%
5. F-Secure, eScan, Panda – 99.2%
6. Symantec (Norton) – 98.7%
7. ESET – 98.6%
8. AVG, Kaspersky – 98.3% (sorry, guys)
9. PC Tools – 98.1% (sorry, @Tenpinmaster)
10. Microsoft – 97.6% (sorry, @meiosis)
11. Sophos – 96.8%
12. Norman, K7 – 96.6%
13. Trend Micro – 90.3%
14. Kingsoft – 80.1%
Reading on in that report and adding in other factors like false positives and scan speed placed Microsoft, AVG, Kaspersky, and McAfee in the second tier while Avast! and Avira are top-tier. Other tests I have seen elsewhere have similar results, and many agree with (or rather, made me decide on) Avira.