Were you a U.S. citizen, a resident alien, or a nonresident alien for the years that you are filing for? If you were a nonresident alien you cannot use TurboTax. You have to file Form 1040-NR, which TurboTax does not support.
If you are not a U.S. citizen, see Chapter 1 of IRS Publication 519, U.S. Tax Guide for Aliens, for definitions of resident alien and nonresident alien.
