Ariolic Disk Scanner vs HDAT2

Ariolic Disk Scanner is a free Windows utility for checking disks for read errors that may indicate drive degradation. It scans every sector on supported media in read-only mode, shows bad clusters as an image, and lists files located on unreadable sectors. The program supports all FAT variants and NTFS. It can scan internal and external disks visible in Windows, including USB sticks, Micro SD cards, CDs, and DVDs. No installation is required, so it can run from a flash drive or another disk. Ariolic says the checks do not alter data. The utility is intended as an early warning for drives showing failure signs, rather than a repair tool. Its knowledge base says scanning does not guarantee that an underlying issue will be fixed. The product page links to a free CNET download.

HDAT2 is a drive-testing and diagnostic program for ATA, ATAPI, SATA, NVMe, SSD, and SCSI/USB devices. Its device-level tools test drives and can repair bad sectors on detected devices. File-system testing covers MBR/GPT, boot data, and directories on FAT12/16/32, exFAT, and NTFS. SMART functions are available for ATA/SATA, SCSI, and NVMe drives. Capacity controls include SET MAX and Device Configuration Overlay, with options to restore full capacity; supported SATA and NVMe devices can also be switched between 512e logical sectors and 4Kn. HDAT2 detects devices on AHCI and some RAID controllers, and USB devices through USB ASPI or BIOS when supported. The main program requires a real DOS system booted from USB, floppy disk, or CD/DVD. A Windows 32/64-bit demo is available, but it operates only at drive level, omits file-level functions, and aborts almost all commands while simulating conflicts. The freeware plan is free, for one or more machines, with redistribution without profit; it is provided as-is without warranty.