To download gmod for free, you must first find a website that offers the software for free. A simple search through the search engines should bring up quite a number of options for you to choose from.
gmod 9, yes gmod 10-no
piggymoo.com has all of stargate, but I'm not sure what gmod is.
Download the playermodel addon from the workshop
You need to download Gmod 9.0.4c when you start there will be 3 choose unmark the Gmod 9.0.4b and your set to go and play gmod 9 online.
you can use gmod in any way you like its pretty much a free roam game where you can spawn things and download addons the gmod website its an awsome game hope you enjoy! p.s. if you dont have a steam account you cant play gmod and you also need a game source by lolkid007
I would recommend garrysmod.org
download them on garrysmod.org, or port them mingebag
download them from garrysmod.org
go to steam.com here are some links related to Gmod to help you: Steam: http://store.steampowered.com/ Download stuff to Gmod here: http://www.garrysmod.org/downloads/ About Gmod: http://www.garrysmod.com/about/ Gmod fourums: http://www.facepunchstudios.com/
go to garrysmod.org (Not all of the girl stuff)
gmod is 10$ at garrysmod.com
umm ok this doesnt make this much since, if your asking if gmod damages your computer, it depends on which gmod you have (if you got it free its gmod 9, if you got it for $10-13 its gmod 10/11). in gmod 9 there were LUA viruses, in gmod 10 there are fake addon viruses so you should just scan for viruses when you download addons (www.garrysmod.org). if you play online there are some players who find it enjoying to spam props and nukes until you crash. also if your computer is lower-end then some of the maps and addons can crash it. but OVERALL no, garrys mod does not damage your computer, some addons and players do. just be careful which addons you download. if your just playing gmod to build contraptions, probably no dammage there. OK now if your asking about some sort of computer in gmod (PCmod?) that damages players or something like that try www.facepunch.com/index.php