cavshell.dll not uninstalling

I had a conflict with other software and had to remove your free firewall and anti virus. An error occurred during the uninstall and left cavshell.dll active. I can not remove it nor can I connect to the Internet with that machine now. I tried reinstalling but that didn’t work either. Any ideas on how I can fix this problem?

My lap top has the same problem… is the competition sabotaging Comodo with this file?

Maybe this will help.
Used at you own risk of course.
External link.
How to unregister DLL in Windows 7-Windows Themes