Annoying Cisco VPN Client

I don't know what's wrong with my Cisco VPN Client software. Whenever I run some programs or install a software, the VPN Client software will try to install itself again -- even if I had already installed it many times. It's seems due to conflicts between EXE and MSI installer. Finally I found the solution -- use Windows Installer CleanUp Utility to remove the MSI installer. Now the annoying VPN Client installer doesn't show up anymore.