My computer froze in the middle of a game. What now?

It depends on the casino policy. Most of them will count the bet as placed no matter what, and the win/loss from the round will be applied to your account when you log in the next time, while some will allow you to repeat your bet. With the account creation and completion of the sign-up process you declare that you agree with the terms and conditions of the casino (whether you actually read them or not) and you should therefore follow these rules.