CrystalDiskInfo is a free, open-source (MIT license) utility for Windows that monitors the health of HDDs, SSDs, and USB drives by reading and interpreting S.M.A.R.T. data. It is widely used by system administrators, enthusiasts, and data recovery professionals to detect drive degradation before failure occurs.
Core Capabilities
- Health Status Display: The main interface shows an overall health rating using a color-coded system: Blue (Good), Yellow (Caution), Red (Bad), or Gray (Unknown). A “Caution” status means deterioration has been detected, while “Bad” indicates the drive may no longer be operating normally.
- S.M.A.R.T. Attribute Monitoring: It displays raw S.M.A.R.T. values for detailed diagnostics. For HDDs, the most critical attributes to watch are 05 (Reallocated Sectors Count), C5 (Current Pending Sector Count), and C6 (Uncorrectable Sector Count). A non-zero raw value in any of these is a warning sign of physical degradation.
- Drive Information: It provides detailed specifications including model, firmware, serial number, interface, transfer mode, temperature, power-on count, and power-on hours. For SSDs, it often shows total host reads/writes, which helps estimate wear.
- Alert Features: The software can be configured to run in the background and alert the user via sound or email if a drive’s health status changes or temperature exceeds a set threshold.
What to Do When a Warning Appears
If CrystalDiskInfo shows “Caution” or “Bad”, the official guidance is clear: back up important data to a different physical drive immediately, before investigating the cause further. A “Caution” status does not guarantee imminent failure, but it means the drive is no longer in a completely normal condition and should be treated as a signal to verify backups and consider replacement. For a “Bad” status, stop using the drive for ordinary tasks and copy data as soon as possible; if files cannot be read or the drive makes unusual sounds, professional data recovery may be necessary.
Usage Notes
- Download Source: Obtain the software from the official Crystal Dew World website (crystalmark.info). A portable (ZIP) version is available, which requires no installation.
- Admin Rights: Some S.M.A.R.T. data may require running the program with administrator privileges to be read correctly.
- Not a Repair Tool: CrystalDiskInfo is for monitoring and diagnosis only. It cannot repair bad sectors or recover lost data. For surface repair, tools like Victoria or MHDD are appropriate; for file recovery, R-Studio or TestDisk are better suited.
