It depends on whether or not the copy is a TurboTax file, that is, has a .tax2018 extension on the file name. If it does, you should be able to open it directly in Turbotax 2018 and step forward to the e-filing stage. In any case, there should a copy of the last save of your return with the file extension of .tax2018 in the folder where the TurboTax program is installed. Hopefully you saved the file periodically as you went along filling out your data so you do not have to go back too far to complete your return.