fhn,
Exactly what are you referring to when you ask if the main Avast program can be prevented at startup?
By removing Avast from the Start Menu using MSCONFIG, you can accomplish your purpose, but in doing so, you have disabled the Auto update features of Avast as well as the resident shields which make it such a great program.
If the program is not loaded, it can't auto update either!
If you only want to disable the Boot scan, that's easy.....right click on the Avast icon in the system tray and go into Settings. Uncheck the button "Test memory during application startup".
Avast actually consumes about 17mb which may be on the higher side, but considering all it does with 3 resident shields in place, it's not bad. Future builds are expected to be on the lighter side so stay with us.
You seem to have more than enough memory on your system to handle a puny little 17mb so why is it bothering you so much? For that you get a top quality AV with both auto update for virus definitions and program updates.....no fuss, no muss.
AND an excellent email scanner for both incoming and outgoing mail!
AND Resident shields on the job all the time!!
What more can you ask for?
I know....less RAM usage.
Give Avast a break. hahahaha