Acer suck. End of.
768Mb not enough for Vista. Bet the video card has a chunk as well.
Scans are important - AV on access scans depend on the sig/dat files having the definition in. It won't if undiscovered (or not in dat). Additionally, sometimes people disable AV to install s/w. Hence scans to mop up those that can bypass.
Never liked Acer, but as mentioned it does look nice, sadly it 's performance is shite.
768mb, first thing I thought was shared graphics.
Scans are important, I totally agree, but for now they are weekly on that Lappy (as it aint mine)
I allways do a scan after a system install and generally keep my software addons till last thing before bed and do a scan when I dont need the PC (overnight)
I will be honest I dont view scanning the PC daily as a critical "Must Do" every day.
Plus the other thing that was eveident, yet annother PC with loads of photo's on it and not one of them backed up. :-/