I actually tried this, and did the full computer scan (all forecasted six hours worth)

Started the scan at 11pm last night, and was expecting to wake up to a full scan completion. Instead, my PC auto-updated at 3am, interrupting the scan.

So I'll try it again this evening.

And I'll agree with the others, AVG blows. I installed it because my Norton subscription ran out and I was looking for a cheaper option.

You get what you pay for...