Disabling file scanning while accessing directories

Hi,



Is there a possibility to disable excessive file scanning while accessing
directories at Microsoft Forefront Client Security? My problem is that the
systems slow down very much if a folder contains a lot of files like .exe,
..cab, .zip for example. If the folder is on a slower drive (network drive or
USB stick) or has dozens of archive or executable files it can take up to 1
or 2 minutes until Forefront has scanned the folder! The CPU load is very
high and the explorer window (or the application that is accessing the
folder) is freezing until Forefront has scanned the whole folder
(MsMpEng.exe).




I my opinion there is no need to scan all files on a folder if it is just
browsed by windows explorer. The on access scanner should only scan a file
if it is executed or opened. Other antivirus Software like Symantec didn't
scan all files.




How can I change this behavior?



Thanks,
Max