Hey Sanjay,
Thank you for subscribing! I've moved your post to a separate thread.
So, yep you will have to first uninstall joomlacomment and then install compojoomcomment.
If you was updating from compojoomcomment 4.1 beta to 4.1.2RC1 - you would not have to uninstall, but this is not the case.
Please first uninstall joomlacomment, then install compojoomcomment.
Another thing! Please read the documentation that I've written:
compojoom.com/downloads/downloads/compoj...omment/documentation
It explains in details the update process.
And again thank you for subscribing