The latest version of Trend Internet Security gives a message at installation: Trend Micro PC-cillin Internet Security 2007 is incompatible with Spybot - Search & Destroy 1.4. As a result, you cannot run both on your computer. Click "Yes" to install Trend Micro PC-cillin Internet Security 2007 and uninstall Spybot - Search & Destroy 1.4, or click "No" to stop the installation.

Anybody who insists on removing other security software before installing theirs is putting their interests ahead of their users' security, and shouldn't be selling security software at all.