This combo are highly likely to accomplish what you need. Hopefully, you don't have any really nasty stuff on the computer that these won't handle. If you do, they will flag it at least in almost all cases, and let you know what has infected you. At times, really nasty stuff requires special treatment... with worst case things ... well, let's not depress you... get back to us if the worst case occurs.
Of course, the best virus protection I have found is to use Linux as I typically do, because of the wealth of bundled or easily available software, especially OpenOffice, GIMP, Stellarium, and many, many games and educational programs, and the apparent lack of ANY real virus or spyware problems with EMail or surfing. I recommend Fedora for desktops and Ubuntu or Mint for laptops as of this hour, but others favor other flavors.
I use AVG, have for sometime now but something is making my computer slow for the last two days. I now have satellite internet, no longer dial up.(praise the Lord) Something is definitely making it run slower and adware/spyware is all I can think of that would cause the problem.
Currently running Ubuntu 8.04 Alpha 6 64 bit variety...Firefox 3 is a bit squirrly....bookmarks especially....