help cant use warlord injector

hi i downloaded a the warlord hook pub and when i click on the warlord hook injector it says: "To run this application, you must first install one of the following versions of the .NET framework:v2.0.50727
contact your application publisher for instructions about obtaining the appropriate version of the .NET framework"

can anyone please tell me what this means and what the problem is and maybe how to fix it? thanks.

download microsoft .net framework 3.5