Have you received your email from TGC?
If not, check in your account on the TGC homepage.
http://www.thegamecreators.com/?m=my_products
You should see at the top a link that says 'View you Steams Keys'
Once you have a Steam copied, open Steam.
At the top left there is a menu that says 'Games', click that and a drop down box should appear.
You should now see, 'Activate a product on Steam'.
Follow the instructions and you should be good to go.
Cheers
Jay.
