Where can i download minecraft forge 1.7.9 for windows 8.1?

Thank you so much for the information. I had no idea you had to purchase it. My 8 year old plays minecraft on my pc and asked to download it and said it was for free. But when I googled it, I couldn't find it anywhere to download (which now makes sense seeing as its a paid item.) Think I should start taking an interest in the game to understand what it is so that the next time my son asked for something to be downloaded, I can make an informed decision.

There isn't forge for 1.7.9 yet, there's only it for 1.7.2 currently. You can get it from here - http://files.minecraftforge.net/...forge.net/ you can also find tutorials on how to install it and use it on the internet. Forge helps with installing mods (Mods add new stuff to the game, which can also be downloaded). And by the way, Tara thought forge was a free alternative to minecraft, which made him/her say that (Just to clear the confusion you had).