Get pywallet
Use the recovery features
https://github.com/jackjack-jj/pywallet

Another thing you can try is moving aside the wallet.dat file (back this up somewhere while you're at it), then moving the entire Bitcoin directory aside, and starting bitcoin again to force it to recreate the directory.  Then, close bitcoin, and move a copy of the wallet.dat back over the newly created one.  The only important file is the wallet.dat, so as long as you keep a good copy of that around, you can get the coins back.