CIS virus signature can not update

May I ask a question about Virus signature downloading and updating?

Version: CIS
OS: Win XP SP3

(1) When I use Update of CIS, It will download a signature file BASE_END_USER_v29500.cav (337MB)

(2) When I use website download from Comodo Anti Malware Database Latest Version & Additions 2022, and then I use manual update. The download file bases.cav (407,637KB) is larger than BASE_END_USER_v29500.cav.

Using above (1), after download, when updating it will show update fail.

Using above (2), manual update will show ok and has signature database ver. 29500. After it, I push update of CIS, two different cases appear:
(2-1) It shows update from BASE_UPD_END_USER_v29501.cav to BASE_UPD_END_USER_v29556.cav. It update ok, but aftrer I turn off and then turn on my PC. The signature database is back to ver.1.

The other case is
(2-2) After I push update of CIS, it shows update back from downloading BASE_END_USER_v29500.cav (337MB). After downloading, when update it shows update fail.

These cases are repeat and repeat. I can not solve it.
Why can’t I update the Virus Signature and keep the final signature?

Welcome to the forum thliang,

The base size variation during direct update and manual update is common because it downloads “*.z” file during direct update. So, base size difference mentioned here is not a problem.

For update issue, please try to locate “cavsedb” folder of CIS on your OS.

If the folder is hidden, please unhide using folder option. Refer enclosed images.

(For your reference: On updated WIN OS it is located at C:\ProgramData\Comodo\Cis\wpTemp\cavsedb)

Please check if there is any files in folder “C:..\Comodo\Cis\wpTemp\cavsedb”. If yes, delete them and try to update CIS and report if it works or not with error snapshot, if any.


Thank you for feedback, Metheni,

I know the folder “C:..\Comodo\Cis\wpTemp\cavsedb”. So I try to update once and snapshot.

  1. I check the “CIS → Help → About”. This time I import bases.cav three times using manual update, but all fail.

  2. I use “CIS → Update (Auto)”. This time it is successful.

  3. The “CIS → Help → About” shows DB Ver is 29570.

I turn off and then turn on my PC. I click the CIS.
4. It shows “The Virus Signature is not Up-to Date”.

I check the “CIS → Help → About”.
5. It shows DB Ver is 1.

These three weeks, the above is repeat and repeat. I can not update CIS.

By the way, I have another PC with WinXP SP3, it can update CIS. I use successfully.

This PC ,I re-installed OS WinXP SP3 three weeks ago, was not successful to use CIS. Originally this PC was OK to use CIS11. One day it showed “The Virus Signature is not Up-to Date”, and DB Ver. is back to 1. After that it could not update till now. Whether it uses CIS10 or CIS11. Whether it installs original WinXP SP3 or re-installs OS again.

That is all.

PS. this PC’s Motherboard clock is failed, I use 3rd-party app to set the system clock when PC turn on and OS start up. This is the only one difference I find with the other PC.

Thank you for detailed explanation thliang, we’ll get back to you soon with a solution.

Hi Thliang,

Please check your Private Message(PM) and provide requested logs.
Thanks in advance.

Kind Regards,

Hi, PremJK

Thanks for your feedback.

What is “Private Message(PM)”? Do you mean “The Comodo Forum > Personal Messages > Inbox”? There is nothing in “Inbox”!

By the way, I am not sure about the meaning of “providing requested logs”. I do not know what is it.


Hi Thliang,

Yes, I have sent a message requesting logs to be provided with steps to follow.

Kind Regards,