I will try to explain what is the basic installation of prim composer.
*Installing the tool
1. Download the tool from here: http://www.mediafire.com/?46x8gdcna7113di
2. Unpack it somewhere
3. Take the "primcomposer" folder and copy/paste it inside your max's "stdscripts" folder, in my case:
C:\Program Files\Autodesk\3ds Max 2011\stdplugs\stdscripts
Note: If you are using 64bit version of max your root folder will be "Program Files" , but if you use 32bit it will be "Program Files (x86)". Make sure you've putted it in the right folder.
4. Start 3ds max. You may get an error on the first start. Ignore it and restart max.
5. You should see a new menu at your top bar called "Prim Composer"
*Configuring your max
There are two major settings you need to change in your max setting in order it to work with prim composer.
1.Customize -> Preferences -> Rendering -> True Color - must be Unchecked
2.Customize -> Preferences -> General -> Use Real-World Texture Coordinates - must be Unchecked
Optional: Set your Display Units to Meters and System Units to Inches