Been using avast! for awhile now on home computer (WinXP Home Ed) and, while it seems to cause negligible interference with opening and running programs, it does really bog down folder scanning in Windows Explorer - in folders with a large number of files in them.
The problem seems to be the loading of the icons or thumbnails (doesn’t matter which view the folder is set to: thumbnails, tiles, icons, list, etc). Scrolling down through a heavily populated folder takes an enormous amount of waiting, as each scrolled page stalls for several seconds while avast! spins away in the task bar reading the assets of every filename being loaded into view.
I’d like to put the programs and DLLs that do all this icon and thumbnail generation into the online scanner’s Standard Shield exception list, but I can’t figure out what Windows system files do this work. I’ve tried excluding explorer.exe itself, along with several suspect DLLs in the \system32 directory, such as the shdoc*.dll files and shimgvw.dll - all with no result (although that last one does prevent the scanner from checking image loading in Windows Fax & Picture Viewer).
Does anyone here have a clue as to just what Windows system files do the work of displaying icons and thumbnails in Windows Explorer, so I can exclude them from on-access scanning?
Any other suggestions regarding the problem are welcome as well.
What are your on-access settings? What OS? What processor? How much RAM, etc.
If your settings are too sensitive (high), yes you may see a slight performance hit. However, I see no impact at all on my lowly amd 1.3 duron just opened windows\system32 with no negligible delay.
I have an AMD Athlon 2000+ w/512 MB of RAM, 80 GB hard drive, running Windows XP Home. Resident programs are just avast!, Kerio Personal Firewall, SpamPal, Norton Unerase Protection and Fileback PC (backup software) - but it’s obviously avast! that’s slowing things down (I always have to wait until the little globe stops turning before my Windows Explorer screens update).
The top part of the dialog you show is the same on my installation, but I don’t even have “scan created/modified files” checked (left it unchecked, as that’s the deault).
I’m afraid the thing you want is not possible.
The list of exclusions contains files that won’t be scanned - not the “programs who will be ignored when accessing files”. So, when you put shdoc*.dll into the list of exclusions, it means that shdocvw.dll file won’t be scanned when it’s opened by some program; however, if shdocvw.dll accesses a file, it will be scanned (unless the target file is in the exclusions list as well, of course).
I am even more baffled than you are as your settings (sensitivity) are lower than mine, I am using, High, with scan all created/modified files. So with a lower setting and a much faster system than mine you shouldn’t be seeing any slowing. There must be something else in the equation/mix.
Open the on-access scanner and make a note of the last file scanned and the number of files scanned. Reduce the size of the windows explorer window so you will be able to see the on-access scanner window when you click on the windows\system32 folder. See what is being scanned (possibly difficult) and make a note of the total number of scanned files after the folder is open.
You might also want to try setting the sensitivity to Normal and see how that works out.
Thanks for your advice. I did what you suggested and it has revealed a lot. [First, though (before I forget), my Standard Shield sensitivity is set to Normal.]
I think I’ve figured it out. The problem is most noticeable when I’m looking at folders with a lot of executable files in them, such as Windows\System32 or the folder where I keep all my installation files from programs I’ve downloaded (I have a couple of hundred install files in a folder called, not surprisingly, Installs).
It seems that Windows has to open every file in a folder to retrieve its embedded icon and, every time it does that, avast! scans the file. This is what’s really slowing down scrolling through folders in my Windows Explorer. It can take up to 10 seconds for all the icons to fill in on a window page, what with Windows retrieving them while avast! is scanning them all at the same time.
Maybe there’s something wrong with my icon cache in Windows … that, or I just have so many different files with so many different icons that Windows can’t cache enough of them for the cache to be of any use. (I’ve got nearly 150,000 files on my 80 gig hard drive - and it’s only half full!)
I’ll see what more I can find out about icon cacheing in Windows (and see if I can up the number the system will keep cached).
I use different views depending on the folder, my mood, or what it is I’m doing with the files at a particular time. I was already aware that icons will load faster in Details view (it’s not that I’ve never noticed any delay before when Windows is loading icons or thumbnails into a folder, it’s just that the delay got much more pronounced (maybe x 5) since using avast!.
After my last post, I did an online search and found out how to increase the size of the icon cache. So, I cleared my cache (using tweakUI) and increased the cache allocation in the Registry. Doing that has made quite a noticeable improvement (at least after the first time I scan through any particular folder during the current Windows session).