Have you since rebooted the computer to clear the "in use" ("locked") data file? Sometimes that works...
Did something happen to your computer or network? Such as...a crash or other improper shut-down on either the computer or AW2K?
Back when I was running old Windows XP, if ever my PC crashed or was shutdown without first shutting down AW, I would get data corruption until I did an AW rebuild. Have you tried a rebuild/re-index?