This has never happened before but 2-3 days ago, I totally uninstalled Avast and re-installed the latest Home version.
I also registered it for the first time - I've never registered an Avast product before. I didn't know why it kept expiring.

Anyway, a couple of days ago, my computer was getting really slow (I'm talking about a 3.2 ghz with 1.5 gigs of RAM here) so I decided to see what processes were running. Well, one of the avast processes was using over 500,000KB of RAM! I terminated it and everything seemed to be fine after that.
Today, it happened again so I looked - 200,000 KB of RAM! Terminated.
Now I want to know if there's a fix for this? A registry fix or something? I'm pretty well versed when it comes to PCs so I can give you more information if you need it or whatever.