Disk Utility Has Locked Drive

Because of a loss of power ScanDisk was interupted before completion. Subsequent attempts to run it results in the following message being displayed, “Scanisk cannot continue because a program such as a disk utility has locked the drive”. My guessis that since it was interupted it never got a chance to clear a control file or flag and it still thinks it is running. What do I do to clear this problem?