DiskWarrior allows you to recover lost files and documents, as well as to rebuild the hard disk directories and files and folders. It also allows you to compare disk versions before and after applying the repair, checking the repaired directory to make sure it is free of errors.
The main novelty of this version is that it is a Universal binary application so that it works natively both on Macintosh based on PowerPC and Intel architecture. According to the developer, it is also a significantly faster version than the previous one. DiskWarrior 4 now also fixes file permissions, including additional tests for files and folders.
DiskWarrior 4 implements a number of other enhancements, including the ability to identify corrupted preference files (.plist files), detect and repair a greater number of disk problems, and repair and rebuild protected volumes using the FileVault feature. Lastly, it also differentiates between uppercase and lowercase file names, fixes attribute B-trees, and file access control lists (ACLs).