http://forum.avast.com/index.php?topic=143167.0
Thank you.
I can’t answer definitively however I can say I am not noticing any memory issue on either xp or W8.1 
Thank you schmidthouse. I was hoping you’d reply.
May I ask if the memory usage in idle is closer to 5 MB (v2008) or to 40 MB (v2011)?
And how can I custom install a new version without uninstalling the current one?
I appreciate your help.
To answer your last question go to control panel> avast antivirus> act like your gonna uninstall it and then switch to the change features tab and select or deselect the shields/features you want or dont want.
Thank you Cast. I appreciate it.
Yaron… don’t update via the GUI. Download the installation files from Avast, and run it (without uninstalling your old version). On the very first screen, in smaller print, you will find the words “Custom Installation”. Click on that, and follow the screens from there, deselecting any aspect of Avast that you do not wish to install. This will do a Custom Install over top of your older version, installing as you requested, and maintaining all of your old settings from the previous version.
Gregg
You can also save your settings and restore them too…works from V8 to V9 too.
Also, a lot of comments on how to do a clean install…I’d tried to summarize in this thread for How-To.
http://forum.avast.com/index.php?topic=143284.0
Seems like most times folks suggest a clean install for any issues.
Obviously, not always necessary but as one comment from one of the experts said on a post “after all a clean install is a clean install”
Thank you GreggH and thekochs.
May I ask your help with the memory issue?
I’ve installed v2013 and the usage is very high compared to v2008. Could you please have a look at your figures?
(Win 7 x32).