LaunchCondition makes sure that the environment the application is being installed into meets necessary prerequisites like OS version, .Net, etc. At the beginning of an application installation the LaunchConditions action queries the LaunchCondition table. All queries must return TRUE in order for the installation to proceed. If any of the items in the Condition column return FALSE a message box is displayed with the contents of the Description column and the installation exits.
Condition:(Not Version9X) And (Not VersionNT=400)
Description:[ProductName] requires Windows 2000 or later.
Table of OS Version9X, VersionNT and WindowsBuild
Note: Besides checking for OS version packagers can also add checks for min IE version, .Net, etc.