Αναρτήθηκε αρχικά από CXGDrCalvinBrown:

soo i can't trade becouse i was on other computer

Newly Authorized Device

If you are on a newly authorized device that has not been Steam Guarded for 7 days you will receive a 7 day restriction from trading and the Community Market. Any other devices that have been authorized for 7 days will be able to trade or use the Community Market.

Actions such as clearing your browser cookies, using a new browser, reinstalling Steam, and reformatting will trigger this cooldown.