I have been using Comodo Internet Security since it’s initial release and it just keeps getting better and better. However whilst trying to install the most recent version 4.0 which was released on March 03 2010 I encountered an installation error 1603. Naturally I cleared all the junk files, disabled unnecessary services, cleared the registry and still couldn’t get it to work until I came across a handy clean up tool which cleans up leftover data from the previous installations.

Prerequisites

Version 4 is a major update so you will need to uninstall any previous versions that exist on your computer. I am assuming that you have already attempted installing the software and have it situated in a folder on your system.

Step 1- Download and Extract Software- Updated 6th September!

There are 2 versions of the Comodo Clean up tool. I suggest that you try the original version first and if that fails use version 2 . Both versions are spyware and virus free.
Extract the file using 7zip or similar. You should now have a folder called CIS Clean-up Tool.

CIS Clean Tool

Step 2-Run File and re-install CIS4

Navigate to CIS Clean-up Tool folder and run the CIS File+Registry Cleaner.bat file. Vista and 7 users need to right click and select run as administrator. Follow the on-screen prompts. This file will clean all associated registry entries, files and folders that have been left over from previous installations.

MS-Dos batch file

To re-install CIS4 navigate to the download folder:

Windows XP C:/Documents and Settings/All Users/Application Data/Comodo Downloader and run CIS_Setup.msi
I am not currently running Vista or 7 so I am unsure where the default download folder is situated.

Your installation should now run smoothly. I would like to thank Ragwing for creating this script. If you have any questions or neither of the above tools work then please feel free to comment below or contact me through my contact form.