Detecting if a program is already installed with NSIS

Question

I\'m using NSIS to create an installer for a program, what is the best way to detect if this program is already installed? Also, since I\'m running the installer from the au

Answer 1

This is generally done by having NSIS insert a registry key for your product when it installs. It is then an easy manner to detect if that registry key is present and if so, bail