Ellie23 said:
What does CCleaner remove?
It does what it says on the 'tin' ... removes all the "crap" you did not know existed ... try it, its free, but heed my warning when installing NOT to install Yahoo Toolbar.
oh, AVG ain't the smartest AV on the block ... AntiVir beats it hand-over-fist, free too ... but hey, whatever you like is better than non at all.
Viruses, or shall I say "True Viruses" are quite uncommon these days, what we see more of is Trojans & Worms, not to mention spyware ... a good AV will stop these also infecting your PC ...