Latest Update / 3.10.102194.530 broken XP DOS path, apps

Updated to 3.10.102194.50 today. Since then XP DOS environment not working.


Start, Run CMD

in dos box enter:

edit testfile.txt

The system cannot execute the specified program

Note: this means it can not find the file which is in the system32 dir and is in the PATH string

in dos box again enter:

edit testfile.txt

This time the dos box hangs.

Yesterday working fine, today after update, and after an uninstall and download of latest version this problem has happened.

Yes, I am having the exact same problem.

I restored my computer (Start>Programs>Accessories>System Tools>System Restore) to an earlier date, and then denied access to the Comodo update. Everything is working well now.

Im have the same problem with all dos-based application.

Windows XP SP3 PL

Im use dos-based ftp program and it not correct run.

Im use restore system files for fix this bug…

All users using dos-based programs don’t install last update!!!

Yep, nearly all my legacy DOS apps rendered useless!

Is there anywhere I can download the version prior to 3.10.102194.530 ?

Hi, please take a few seconds to search the forums:

It seems we have a bug with 16 bit applicaitons. We will fix this issue this week. Until we fix it, a temporary fix would be renaming guard32.dll in c:\windows\system32\guard32.dll to something else and restarting your computer. When we update CIS, you can restore it back.

Sorry for the inconvenience.

With all due respect I think my opening post on this thread was one of the first to point out this problem. The other threads did not exist at that time :slight_smile:

Thanks for the pointer. I can confirm the renaming of guard32.dll is a working temporary fix.

Yes, I am having the exact same problem.
taday i update my comodo to lastest one, that is begining of nightmare.
because i use the CMD every day for work.
Finally i uninstall it, reinstall old version ,then it is ok,.

please fix the bug,i want to use the lastest one

Wei, try the guard32 fix.

rename the following file


to something like


If you now open a new DOS box your apps should be fine.

I think Comodo tries to repair this with an update so make sure you temporarily turn off auto update (and don’t manually update) as AFAIK it will try to replace the file.

Obviously let it update when a proper fix is out.

Update to the latest version (.531) as it fixes this problem. Run the program updater from Miscellaneous → Check for updates.

Thanks for the update (.531). It works!