If not already in Avast, it is a good idea to integrate Smart File type detection feature/option into Avast so that Avast automatically recognizes a file’s type without relying on it’s extension. And once Avast has known a file’s extension, then Avast could check to see if it’s infectable and if it is, the file is scanned for malware. But if not, Avast skips the file and reducing the load of the Standard Shield. It will also increase detection since some files hide in extensions that aren’t checked? 
This is already implemented and, if I’m not wrong, called ‘virus targeting’.
This is transparent in the Professional version (there is a setting for that).
Other questions:
Disable automatically contacting updates server: see ‘settings’ link bellow in my signature or just configure it to ‘Manual’ (settings > Updated (Basic)).
Customize heuristics. Go to the provider settings (Internet Mail and Outlook/Exchange) and configure it 
(you have to choose ‘Custom’ level of protection).
I can’t find such thing anywhere?
I only have Standard Shield installed btw.
Maybe the Standard Shield has this feature, but certainly the “Quick” scanner does not. >:(
Scanning a drive where I kept my Virtual PC images, Avast’s Quick Scanner toke ages to scan a non-infectious file… Those image are about 1GB each.
Could anyone confirm this? :-\
Actually not. It can be configured. Do you have avast Home or Pro (the configuration windows are only available in the Enhaced User Interface, i.e. Pro version only…).
I have the Pro version and after checking the the Advanced Configuration box in Scan jobs, I see that Ignore virus targeting is checked. (Virus Targeting isn’t Smart Type Detection though.
I also see that types could be configured to name extension (fast) but it seems that Smart Type detection cannot be configured?
Does unchecking the Scan All Files do it?
Sure. “Ignore Targeting” is something a bit different. You need to uncheck the 'Scan entire files" on the same page.
You mean that unchecking “Scan All Files” will require you to uncheck “Scan entire files”?
I would like to leave Ignore Targeting checked to make sure the detection is as good as possible.
Scan All Files – opens even files such a .jpg and .gif.
Scan Entire Files – if a file is 1GB in size, scans it whole even if it thinks it’s not really necessary.
The main performance boost will be seen if you uncheck “Scan Entire Files”.
If I were to uncheck Scan All Files, would Scan Entire Files override that setting?
They are too different things. In normal cases, you’d have both those options turned OFF.
I have Scan All Files off while Scan Entire Files is on.
It seems that Avast is now detecting infectable file types before scanning the file. If I were to uncheck Scan Entire Files, would I miss any viruses because of that? I mean what about viruses that does not hide at the starting/ending portions of a file?
What file types could Avast Smart Detection detect?