What is hard drive test short DST not available?

Hard drive diagnostics are an important tool for testing and monitoring the health of a computer’s hard disk drive. The hard drive test (DST) is one such diagnostic test that is built into many hard drives by the manufacturer. DST allows users to quickly assess the drive’s functionality and detect any errors or problems. However, some users have reported seeing a “DST not available” message when trying to run this test on their hard drives. There are several potential reasons why the DST might not be available.

What is Hard Drive Self-Test (DST)?

The hard drive self-test, also known as drive self-test (DST), is a built-in diagnostic program on many hard disk drives. It is designed to gauge the drive’s performance, scan for errors, and determine if any sectors are damaged or unreadable.

DST tests are embedded in the drive’s firmware by the manufacturer. They put the hard drive through a series of read/write tests to simulate different types of operations. DST allows the drive to scan itself for any faults or issues.

Running DST regularly can help identify problems early before they lead to larger failures. The test can also be used to monitor drive health and performance over time. Many drive manufacturers provide DST utilities that users can run from within the operating system.

Why Perform a Hard Drive Self-Test?

There are several benefits to performing regular hard drive self-tests:

  • Detect bad sectors – DST checks for sectors that cannot reliably store data due to damage or errors. This helps identify potential drive failures.
  • Check drive health – The self-test gauges overall drive performance and health by stressing the read/write heads, spindle motor, and data transfer speeds.
  • Identify problems early – Running DST periodically enables early detection of hardware issues before they become catastrophic failures.
  • Monitoring drive health – Comparing DST results over time can reveal gradual performance degradation and early symptoms of hardware problems.
  • Troubleshoot issues – If your computer is experiencing unexplained crashes, file corruption, or data loss, DST can help diagnose if the hard drive is the cause.

In summary, hard drive self-tests provide an invaluable tool for predicting, diagnosing, and avoiding hardware failures. Regularly monitoring drive health with DST can help prevent catastrophic data loss.

Why Does DST Show “Not Available”?

There are several potential reasons why the hard drive self-test or DST may not be available when trying to access it:

Drive Does Not Support DST

Older hard drives may lack built-in DST capabilities. DST first started appearing in ATA drives around 2001-2003. Very old drives predating this era likely do not have self-test functions embedded in their firmware by the manufacturer. Upgrading to a newer drive with DST support can allow you to benefit from drive self-diagnostics.

Missing or Corrupted DST Utility

Most hard drive manufacturers provide a DST utility that enables users to execute self-tests from within their operating system. If this utility is corrupted, erased, or improperly installed, it may cause DST to be unavailable. Reinstalling the manufacturer’s utility or trying a third-party DST tool can often resolve this.

Outdated Drivers

Using outdated or incompatible drivers for your hard drive controller/chipset can also result in DST being inaccessible. Check that you have the latest drivers from your system/motherboard manufacturer and hard drive vendor. Updating to the newest drivers may enable DST if older ones are causing issues.

Damaged System Files

Corrupted system files, boot sectors, partitions, or operating system errors can sometimes disable the DST feature. Running the CHKDSK utility may help repair damaged system files. A clean reinstall of your OS could also restore full DST functionality if software issues are preventing it from working properly.

Faulty Cable Connections

Loose, damaged, or improperly connected data or power cables between the hard drive and motherboard can cause DST to show unavailable. Reseating cables, swapping in new ones, or connecting the drive to another computer can help determine if faulty cables are to blame.

Hard Drive Defects

In some cases, undetected physical damage on the hard drive itself may be responsible for DST not working. Severe media corruption, failed read/write heads, motor issues, or degraded PCBs can prohibit the drive from running self-tests properly. A mechanically defective drive may need to be replaced.

Hard Drive Firmware Issues

Bugs, glitches, or corruption in the hard drive’s firmware can also result in DST not functioning as intended. Updating to the newest firmware from the manufacturer may rectify these sorts of problems.

How to Run DST When “Not Available”

If the built-in hard drive self-test is not available, there are still options to perform diagnostics:

Manufacturer DST Utilities

Most drive vendors provide their own DST tools that can be downloaded and run on your computer. These utilities work independently of the built-in DST in the drive’s firmware. Popular examples include Seagate SeaTools, Western Digital Data Lifeguard Diagnostics, and Hitachi Drive Fitness Test.

Third Party Diagnostic Tools

Alternatively, many third party hard drive utilities have drive self-test capabilities, such as:

  • HDTune
  • MHDD
  • HD Tune
  • DiskCheckup
  • Hard Disk Sentinel

These tools may be able to perform diagnostics even if the native DST is unavailable.

Bootable Diagnostic Media

Booting from a USB drive or CD/DVD with a bootable hard drive diagnostic suite can often enable DST when it cannot run inside the main operating system. Examples include UBCD, Hiren’s BootCD, and Ultimate Boot CD.

SMART Monitoring

SMART (Self-Monitoring, Analysis and Reporting Technology) monitors internal hard drive attributes and error rates to predict failures. SMART tools can provide some diagnostics even if DST is not available.

Solution Description
Manufacturer DST Utilities Download diagnostic tools from your hard drive brand like Seagate SeaTools, WD Data Lifeguard, etc.
Third Party Diagnostic Tools Use disk utilities like HDTune, HD Tune, DiskCheckup, etc. which have drive self-test features.
Bootable Diagnostic Media Boot from a USB or CD/DVD with diagnostic software like UBCD, Hiren’s, etc. to run DST.
SMART Monitoring SMART tracks drive attributes and errors to predict failures even if DST is unavailable.

When to Be Concerned About DST Unavailable

A “DST not available” message can sometimes be resolved with a simple driver update or reinstalling your disk utilities. However, it is worth being cautious once DST becomes inaccessible, as it can also signal potential hardware issues:

  • If DST was previously working, but now consistently shows unavailable, it may indicate a new problem or developing failure in the drive.
  • Accompanying serious symptoms like frequent crashes, slow performance, unusual noises, or SMART errors would warrant greater concern.
  • On older drives, the lack of DST could simply mean missing capabilities. But if DST disappears on a previously working new drive, it is likely a defective component.
  • If no solutions can re-enable DST on a drive, it may have irreparable physical or firmware damage requiring replacement.

While an unavailable DST does not necessarily mean the drive is about to outright fail, it takes away an important health monitoring tool. Combined with other issues, it should raise suspicion about potential faults requiring further diagnosis. Always backup important data if DST is persistently unavailable.

Example DST Scenarios

Below are examples of common scenarios that can lead to DST being unavailable:

ST3000DM001 3TB Drive – Missing DST Utility

A 3TB Seagate Barracuda ST3000DM001 fails to run DST. The user cannot find the SeaTools utility on their system.

Potential Solutions:

  • Download and install the newest SeaTools for Windows from Seagate’s website.
  • Boot to the SeaTools bootable ISO to run DST outside of the main OS.

WDC WD10EZEX 1TB Drive – Unrecognized in BIOS

A Windows 10 system with a 1TB WD Blue WDC WD10EZEX cannot detect the drive in BIOS or Disk Management. DST is unavailable.

Potential Solutions:

  • Check SATA cable connections and try a different SATA cable.
  • Test the drive in another computer or external enclosure.
  • If still not recognized, the drive electronics may have failed requiring replacement.

ST1000LM024 1TB Laptop Drive – SMART Errors

A 1TB 2.5″ Seagate laptop drive in a Lenovo Yoga begins showing SMART warning thresholds exceeded. DST cannot start.

Potential Solutions:

  • Update laptop chipset/SATA drivers from Lenovo or Intel.
  • Run SeaTools for DOS on bootable media to do read tests.
  • The drive may be failing – clone data and replace drive.

How to Repair Drives with DST Issues

If running DST verifies read/write problems on your hard drive, there are some repairs you can attempt:

Run Manufacturer Low-Level Format

Performing a full format through a manufacturer tool (ex: Seagate Low Level Format Tool) can remap bad sectors detected by DST and refresh drive performance. This erases all data.

Clean the Drive Heads

Gently cleaning the read/write heads with isopropyl alcohol can help resolve media errors in some cases. This temporarily restores performance.

Update Firmware

Updated firmware from the manufacturer may fix buggy behavior causing DST to malfunction. However, firmware updates carry a slight brick risk.

Replace Cabling

If DST detects interface errors like CRC errors, replacing worn SATA cables can allow more reliable data transfer between drive and system.

Disable/Reduce Write Caching

Turning off the drive’s write cache feature may resolve intermittent DST failures related to data caching algorithms. This impacts performance.

However, if the hard drive has physical media damage or unrecoverable read/write heads, repairs will likely be temporary or impossible. Failing drives should be cloned and replaced once persistent problems appear.

Best Practices for Avoiding DST Issues

You can help minimize the chances of a “DST not available” error using these best practices:

  • Keep your system and drive firmware updated to the latest stable versions.
  • Periodically defrag your hard drive to prevent excessive file fragmentation.
  • Maintain good ventilation around your hard drive to prevent overheating.
  • Use a surge protector to guard against power spikes damaging drive electronics.
  • Always eject and disconnect external drives properly to avoid corruption.
  • Regularly back up your data in case DST does detect drive problems.

While unavailability of the DST diagnostic can be frustrating, it serves as an important early warning of potential issues warranting further attention. Using the solutions outlined, you can often restore access to this vital tool for monitoring drive health and troubleshooting problems.


The hard drive self test or DST is an invaluable diagnostics tool for confirming drive functionality and avoiding catastrophic failures. When the message “DST not available” appears, it typically indicates an underlying issue preventing access to this utility.

Causes can range from missing DST support on older drives, corrupted drivers/utilities, buggy firmware, mechanical defects, or connection problems. Updated OS/hardware drivers, reinstalling DST tools, replacement cables, drive repairs, or wholesale replacement of the hard drive may be necessary.

Alternative diagnostic options like manufacturer/third party tools, bootable media, and SMART monitoring can help test drives when built-in DST is unavailable. But users should address the root cause, as disappearing DST capabilities often foreshadow larger looming hardware problems. With proactive troubleshooting, you can restore this vital first line of defense and maximize your hard drive’s lifespan.