Ariolic Disk Scanner vs MHDD

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.

MHDD is a freeware utility for low-level hard drive diagnostics and management. It supports IDE, Serial ATA and SCSI drives, and can access USB storage through USB-to-SCSI emulation drivers. Diagnostic tools scan drives, show SMART attributes, run tests and log scan results. Drive operations include low-level erasing, sector reads and writes, bad-sector remapping, and changing drive size with HPA. A simple scripting engine and batch-file support allow tests to run without an operator. The maker offers the software as a CD image, self-extracting floppy image or archive of executable files. The manual lists an Intel Pentium or higher, 4 megabytes of RAM, a keyboard, and DR-DOS or MS-DOS 6.22 or higher as requirements. It notes that some AHCI controllers may not be recognized, with IDE or Legacy mode suggested if needed. The manual warns that MHDD can damage a drive or cause data loss, particularly around erase or remap operations, and advises backing up first. It also says the tool is difficult for people without deep knowledge of disk drives. MHDD is listed at free.