Can not update virus database

Since about a week now i can not update my virus database. I keep failing at finalizing at 90%. Comodo tells me to check my connection and try again. There is nothing wrong with my connection. Please help me, i like Comodo, but the virus update has to work for me to continue using it.


Try running Diagnostics and see if that can fix it. On what version of CIS are you?

Thanks for responding. I did as you suggested and ran the Diagnostics, and it says there is nothing wrong with the installation.

My CIS version seems to be 5.12.256249.2599
The virus signature database version is 17284

Let me know if there is any other information you might need. I am running Windows XP if that is of any relevance.

Please try the following. Download the latest available full av database and apply it as described in Where can i download the latest full AV database?.

After that run the av updater again to get the incremental updates and see if that does the trick.

Should i use this one?

  1. For CIS 5.8 - 5.10

As my version starts with 5.12.

You can use that one.

I will update that page so that it will state 5.8-5.12.

Have not had the time to do this yet, but i will try to this weekend and update you on the situation.


with post title problem, I have downloaded the CIS, installed without removing the old.

Again, virus update is not working, now it’s not working the firewall either, I have switched to the WIN7 firewall.

I have run diagnostics but the problems couldn’t fixed, I have the xml report file, where should I send it?


Could you try a clean installation of CIS? When reinstalling CIS please follow Most Effective Way to Reinstall CIS to Avoid/Fix Problems by my colleague Chiron. It will provide a reliable and clean starting point.

When you want to keep your current configuration remember to export it to a folder that is not a part of the CIS installation so you can later import it again.

I’ve had the same problem. Prior to trying a clean reinstall, I thought I’d point out there may be a problem with the database file. When trying to decompress it with 7zip, I get a diagnostic message from 7zip, "Unsupported compression method for ‘BASE_END_USER_v17425.cav’.

This seems to be a fairly widespread problem. There is a more involved discussion of it in this same forum subheading here:

As far as I can tell, nobody has a real solution yet. (I don’t consider advice to constantly uninstall and reinstall a real solution.)

In my case, I find that when I reboot my pc the virus definition updates resume working again for several days. But then they stop again with the same old error you describe “Update Failed. Please check internet connection…” etc.