May be the update didn't work out well. Please try a clean install and see what happens. From what version did you update by the way?
Start with exporting your configuration to a folder that is not part of the Comodo folder under Program Files. This way you can restore your configuration after the reinstall.
Uninstall CIS and reboot. Then run Comodo System Cleaner
to get rid off registry keys.
Then delete the Comodo folders under Program Files, Program Files\Common Files, C:\Documents and Settings\All Users\Application Data\ .
Users\%username%\appdata\local\, Users\%username%\appdata\roaming\ and \Users\%username%\appdata\local\virtual store
To be even more thorough open Device Manager and set it to show hidden devices under menu option View. Then see if there are Comodo driver(s) left in non Plug and Play drivers. If so select the driver --> click right --> uninstall and reboot.
Now delete the following:
C:\boot.ini.comodofirewall (this file may not exist).
WARNING: Do not mistakenly remove the original “boot.ini”.
CSC will forget the following keys:
HKEY_CURRENT_USER\Software\ComodoGroup\CFP and HKEY_CURRENT_USER\Software\ComodoGroup\Comodo Internet Security
*(If you have other Comodo products installed, delete only the values
Please delete them by hand.