AntiVirus scan causes high CPU usage

Hi, I recently updated my CIS today and had a virus scan and I noticed that my computer is slowing down so I checked on process explorer and noticed that cmdagent.exe is eating cpu usage up to 80% … I thought there was something wrong with COMODO… so what I did is

  1. Uninstall Comodo
  2. ran Comodo removal tool and Ccleaner
  3. reinstall comodo
  4. update antivirus

Now, everything was smooth in scanning… later, I updated comodo (Program update) and after restarting I ran antivirus scanning again and there it goes back again, high cpu usage… It seems like there was something wrong with the update that causes high cpu…

I hope there will be a fix for this… I love comodo and I don’t want to switch to other AV programs… thanks

My Computer Specs:

  • quad core q8400
  • 4 GB Ram
  • windows 7 ultimate

P.S. sorry for my english

Best thing to do to make sure that there are no left overs of previously uninstalled security programs around. Not all uninstallers do a proper job. And left over applications, drivers or services can cause all sort of “interesting effects”.

Following are two of my tutorials to make sure there are no more left overs.

Use existing removal tools

Try using removal tools for those programs. Here is a list of removal tools for common av programs: ESET Knowledgebase .

Otherwise do a Google search with terms “removal tool” and * name of product or vendor*.

For a more technical hands on approach:

We are gonna take a look to see if there are some old drivers of your previously uninstalled security programs are still around. First run "set devmgr_show_nonpresent_devices=1’ without the quotes from the command prompt.

Then go to Device Manager → View → show hidden devices → now look under Non Plug and Play drivers → when you see a driver that belongs to your previous security programs click right → uninstall —> reboot your computer. You need to Google the driver’s names to see to what programs they belong to. You don’t want to uninstall Microsoft/Windows related drivers of course; some Microsoft drivers may show up as non active please don’t uninstall them. It is best to make a system restore point before this of course.

When the problem persists make sure there are no auto starts from your previous security programs. Download Autoruns and run it.

This program finds about all auto starts in Windows. This tool can therefore seriously damage Windows when not handled properly. After starting push Escape and go to Options and choose to hide Windows and Microsoft entries, to include empty locations and then push F5 to refresh.

Now check all entries to see if there are references to your previous security program. When you find them untick them. After unticking reboot your computer and see what happens.

I’m seeing something similar. I have Comodo pro installed on my Dell laptop running XP Pro SP3, and after a recent Comodo update my scanner software is dog-slow. I removed comodo and now the scanner software (HP PrecisionScan Viewer) is screaming fast again.
This is the second time I’ve seen this behavior. The first was about a year ago and I suffered through several months of poor performance until it magically cleared up after another Comodo update. Any idea what’s causing this?

–Update: I reinstalled Comodo ISP and the scanner’s running slow again. It appears as though the real-time scanning is virus checking the file (or memory) being created by the scanner as the scan is taking place. Unfortunately it rechecks the file every time I adjust the size of the area being captured in the scanner window, slowing performance to a crawl and making me wait several seconds every time I try to make a change. I added the HP scan executable to the exclusions list, but the same slow behavior continued. When I disabled antivirus protection the slow behavior went away, so I’m certain this is the problem.

–Final Update: I played around for a bit and discovered that if I excluded the entire Hewlett-Packard directory “C:\Program Files\Hewlett-Packard*” Comodo would no longer interfere with the flatbed scanner software. Currently both Comodo and the scanner software are up and running with no ill effects on either side.

It would help Comodo greatly if you would consider filing a bug report on this.

If you have time and feel like it you can post the report in the Bug Reports - CIS board following the format as described in FORMAT & GUIDE - just COPY/PASTE it!.

I always use removal tool after uninstalling previous antivirus… and I had been using Comodo antivirus for over 6 months… and the problem only started after a product update last March 1 and I had to switch to other antivirus since I wasnt able to fix the problem.