A myslíte ze nepomuze ani tohle - Authorizing a Steam Account on a New Computer
How do I authorize my account on a new computer?
In order to authorize your account on a new computer, you will need to enter in a verification code that is sent to the email address registered to your Steam account.
If you are unable to access the email address on the account, please see the Changing the Contact Email for a Steam account FAQ.
If you no longer have access to your other computer or your email address, please contact Steam Support.