Win7-64, cannot install anything while Avast file system shield active

[DoktorV]

I just finished installing Windows 7 64-bit on a new computer and installed Avast free edition without difficulty on it, but I cannot install anything else while Avast file system shield is active. Installers always crash or lock up even with heuristics off and code emulation off. I have selectively disabled the other shields and they do not seem to have any effect on this problem, only the file system shield.

[Lisandro]

Most probably the issue is on Behavior Shield. Can you test disabling it?

[DoktorV]

I tried that before and couldn't install anything, but I was attempting to install system software and drivers then. On your suggestion I've tried again and I've found that programs and games install successfully while Behavior Shield is off but device drivers do not.

[pk]

What do you mean by "Installers always crash and lock up" - does installer crash or entire computer? or does it freeze, or something?
Which app do you try to install?

Thanks.