Not responding and I'm losing my work when I reopen

I installed ADE in 3.0 but it kept freezing (not responding) so I downloaded it in the 2.0 instead.  It freezes less, but when it does and I have to close it, I lose all my work.  I have been highlighting for hours for nothing!  Please, please tell me how to make sure I don't lose my work when the program stops responding and I have to restart it.