To be more precise: do I need to uninstall Avast (i.e. the main/whole program, not the AV database) prior to upgrading it “manually” (meaning to upgrade it through the “setupeng.exe” installer)??
You see, the thing is that I am still (I know, I know) on a slow connection and the last time that I’ve chosen “Updating – VRDB” (yes, and not “Updating – Program”), the updater attempted to download approx. 23 MB of data. And today I went to my mum and on her computer I downloaded the latest installer version: 4.8.1335.0, date: 15.3.2009 (compare to install-package version: 4.8.1229.0, date: 15.10.2008 with which I’ve installed my current installation of Avast), and so I am curious do I need to first uninstall the currently installed Avast main program or could I just install the latest version (again, the one downloaded today a few hours ago) over the already existing one?!
You should be able to over-install, though I don’t know if the avast self-defence would have something to say about that (you may have to disable it). Program Settings, Troubleshooting, Disable avast! self-defence module.
Why would you want to do a manual update by downloading the full 27MB file (though the faster connection on your Mum’s computer is good) ?
You could just do a manual program update from avast which should be much smaller than either the virus signatures VPS (not VRDB) at 23MB or the full program at 27MB. Probably in the order of a few MB.
I am just reporting back that I managed to do it the way you suggested (i.e. with “self-defence” module turned off), actually, the installed detected already installed Avast! and so there was this “Update” option (beside “Remove” and/or “Repair”, not sure anymore)