HardDiskValidator is a Windows Forms application for testing hard drives for bad sectors and verifying disk integrity. It provides multiple test modes: read-only scan, read + wipe damaged sectors + read, read + write + verify + restore (non-destructive), and write + verify (destructive). The application uses the DiskAccessLibrary.Win32 NuGet package for low-level physical disk access, requiring administrator privileges. It features a visual block map showing test progress and results, with logging and speed display. The code is well-structured with clear separation between disk I/O (DiskReader, DiskTester) and UI (MainForm, UIHelper). It targets multiple .NET frameworks (2.0, 4.0, Core 3.1) and includes ILMerge for single-file deployment. The repository is a single-project solution with no tests, but the core disk testing logic is robust and handles I/O errors gracefully.