Nobody can make tax programs backward compatible. Each year is completely separate. The tax laws and rules and forms change too much each year.
And for people trying to open the .tax file in the same year program (one person above was trying), After you get the program reinstalled the first thing to do before you open your tax return is to update the program and install any state programs you had. Then open your file. So you first might need to start a fake return to be able to download the state program (go to File-New Tax Return).
Then go to FILE -Open and find your return.
