If you cannot trade with a message stating that you cannot trade due Steam Guard... the message you get is: The reason for Valve is to better protect their users who do trade, for Steam Wallet money can now be traded, and better prevention of hijacking of accounts that are active in trading. The solution is to activate SteamGuard, and once its enabled, to wait for 15 days before you can trade again. Open steam. Go to top left, and click "Steam", and select "Settings": In this dialog screen, make sure that the "Contact Email" is "Verified" by letting it send you a email, and you confirming the email by clicking on the sent link by Valve. Once your email is verified, make sure via the "Manage Steam Guard account security" button that its ENABLED: With the optional tick box "Deauthorize all other computers now" you can remove steam guard access to any other computer (requiring them to use a steam guard code to activate). Wait after done the above for 15 days to be able to trade again or use the Steam Market place. Notes: If you have been hijacked, and steam support restored your access, you won't be able to trade till you have had steam guard enabled for 15 days. Once steamguard is set to enabled, it doesn't mean its activated, it takes 3x logging into steam after been verified with your email.