Keeping this guide up just in case but, from the comments it seems as though this no longer works in November/December of 2020. Really a shame because I figured out how to get this working in 2016 and was amazed that it was working for so long. All we can hope for now is another workaround or a mod for dedicated servers.

Servers for this game are not down! Infact the login servers work fine it's just that stupidly, steam doesn't give you an admin notification to allow the game to use your internet. This is why the server fails to contact the key.

To fix this, first off right click your game > Properties > Local Files > Browse Local Files.



Next off click the Binaries folder, scroll down until you see the "RainbowSixVegas2_SADS.exe"



Run this and an Admin notification should come up about network and if you'd like the program to use your internet, press yes.

Once this is done, go back to steam and run your game until the main menu. Once at the main menu, click 'Online' and wait for the box where you enter your game key comes up.

If you don't know what your key is, you can find out by once again right clicking your game and clicking "View CD Key"


A box will come up showing you your key, enter your key into the boxes that are in game.

The next thing needed is a UPlay account, the page rainbow six will take you to is broken, but don't worry! All you need to do is go to Uplay Account Manager[account.ubisoft.com] and create an account. (IF YOU ALREADY HAVE A UPLAY ACCOUNT, YOU CAN USE IT!)

Once this is done, login and there you go! You're now able to play multiplayer, terrorist hunt or Co-Op! Enjoy killing terrorists and kickin' butt with friends!