If a state id number is not printed on your paper W-2G, then you can use the "Federal ID" number in its place, or an even better idea would be to contact the state that issued your form; there should be a phone number listed.
Please note: If your winnings are in a state that does not have a state income tax, you will not need to enter any state information. In this case, you will leave all the information in boxes 13-18 blank because you will not have a state reporting requirement in state's without income taxes (Alaska, Florida, Nevada, South Dakota, Texas, Washington and Wyoming currently have no state income tax.
Lastly, If you are not entering an W-2G, click the ''Back'' button and then ''Skip W-2G''. You can enter you winnings not reported to on a W-2G here.