reinstall the program, try to uninstall it with
Bitcoiners should be very careful be allowing software to be installed from anywhere, including something like this.
The error is likely due to an improper shutdown (either app crash, or windows crash, or power interruption) in which the automatic recovery of the database wasn't successful.
Firstly, make sure you have a backup of your wallet.dat (but don't overwrite a previous backup).
The debug.log will help show which database the program is having trouble with.