i think you have to do a scan of yr harddisk
1) AVG is just a free AV software and it take up alot of
resource and slow down yr system. It is not very powerful to
capture the virus lar.
- Just do a scan with yr AVG see whether any virus
detected??
2) Before you install a better one pls unstall AVG (normal
procedure - pls take note only 1 antivirus is allow to install on
yr pc !!!!!)
1) anti-malware
2) Norton Antivirus (need to pay or borrow from
someone)
http://en.wikipedia.org/wiki/List_of_antivirus_software
3) McAfee
4) Others