addons help newbee

using 2.55 beta–i hve real trouble installing scripts–i know they hve to be in scripts dir–once installed i go to user preferences and select them–i have installed a plug in greenbutton, i find under render in my preferences files a bunch of renders all grayed out–i find the greenbutton ( i am using this as a example of my problem and i know i can go to their site for help but i feel the help need is more generic–any help a this point really is appreciated-- i have installed the script on my desktop for easy location

You have to check the box to the right of the addon you want to enable. Is that what’s got you stumped?
If you want it that way permanently, then load the default blend file, enable whatever addons you want, then press ctrl+U to save it as the new default configuration