Make sure you have MDKSetup.msi, Setup.exe and Setup.ini all in the same folder. To install the MDK, run Setup.exe and follow the instructions. On the first page, the location of the installation should be the same as where you installed the game. Keep the "Just me" radio button selected.
If the MDK installer does not complete because the .Net framework is not installed, you can get the .Net framework from the following url:
Click on the "Download" button to get the file dotnetfx.exe, version 1.1.
Some machines may have problems with installing from mapped drives. If the installer fails with the message "The installer was interrupted" you can fix this by making sure the setup files are on the same drive you want to install to.
Once the installation has completed, you can run the launcher application from the desktop. From the lanucher, go to the "Documentation" tab and click on the "User Guide" button. Please read the "Getting Started" document to see how to use the MDK. To make sure the tools work properly with each other, it is best to follow the recommended steps for creating a mod as described in the Getting Started document.