Why Early Detection Matters
A hard drive that fails completely with no prior warning is rare. More commonly, a drive fails gradually — and during the gradual failure phase, your data is still accessible and still recoverable.
The window between “starting to fail” and “completely failed” can be anywhere from a few days to several months. Recognising the signs during this window means you can back everything up, plan a replacement, and avoid a data recovery situation entirely.
Sign 1: Unusual Noises (HDDs Only)
Mechanical hard drives (not SSDs) make noise. A healthy drive produces a faint, consistent hum from the motor and occasional quiet clicking as the heads seek across the platters. You typically don’t notice it.
Warning sounds:
Clicking: A repetitive clicking sound — sometimes described as a “click of death” — is the most serious warning sign. It indicates the read/write heads are failing to find their target position and resetting repeatedly. This sound means the drive is likely to fail soon. Back up immediately and stop using the drive for anything non-essential.
Grinding or scraping: A grinding noise means the read/write heads are making contact with the platter surface. This is causing physical damage to the platters and the heads simultaneously. Every rotation is making the situation worse. Power down immediately.
High-pitched whine: A change in the pitch or character of the drive’s normal sound — particularly a new high-pitched noise — can indicate bearing wear in the drive motor.
SSDs are silent. An SSD that’s failing gives no audible warning — which is one reason SMART monitoring is important for SSDs.
Sign 2: Progressive Slowness
A computer that has become noticeably slower over several months — not due to software changes or new applications — is often pointing to storage problems.
Hard drives slow down as sectors develop faults. When the drive tries to read a sector and encounters an error, it retries multiple times before reporting the failure. These retries take time and cause the system to stall, which manifests as general slowness, long file open times, and programs that take longer to launch than they used to.
This differs from the slowness caused by a full drive, too much background software, or insufficient RAM — which also causes slowness but in different patterns. Storage-related slowness typically involves longer delays on specific operations: opening files, saving large documents, or loading frequently-used applications that load consistently fast on a healthy drive.
Sign 3: Files Becoming Corrupted or Unreadable
A file that was fine last week and is now corrupted or won’t open is a significant warning sign. This happens when the sectors storing that file have developed read errors — the drive can no longer read the data it previously wrote.
Similarly, applications that crash on startup (when they were previously working), or games/programs that produce errors about missing or unreadable files, can indicate storage problems.
If you notice this happening with multiple files, treat it as urgent. It indicates the drive has already developed bad sectors and the fault is progressing.
Sign 4: Operating System Errors and Blue/Black Screens
Windows:
- BSOD (blue screen) errors with codes like UNMOUNTABLE_BOOT_VOLUME, CRITICAL_PROCESS_DIED, PAGE_FAULT_IN_NONPAGED_AREA, or 0x0000007A often indicate storage problems
- Frequent freezes that require a hard restart
- “The disk structure is corrupted and unreadable” error messages
- Event Viewer (search for it in the Start menu) showing repeated disk errors with Event ID 7, 11, or 51 from the “disk” source
macOS:
- “Disk Utility First Aid” finding errors it can’t repair
- The spinning beachball (rainbow wheel) appearing constantly
- A question mark folder icon at startup (drive not found)
- Kernel panic crashes that reference storage
Sign 5: SMART Data Warnings
SMART (Self-Monitoring, Analysis and Reporting Technology) is a built-in diagnostic system in both hard drives and SSDs. It tracks dozens of internal metrics and flags when values fall outside safe ranges.
Windows and macOS don’t prominently display SMART data, but free tools make it easily accessible:
- Windows: CrystalDiskInfo (free download) — shows SMART status as Good, Caution, or Bad
- macOS: DriveDX, or via Terminal with
smartctl -a /dev/disk0
SMART attributes to watch:
- Reallocated Sectors Count: The number of bad sectors the drive has found and replaced with spare sectors. Any value above 0 is a warning sign; a rising count is serious.
- Pending Sectors: Sectors flagged as potentially bad that haven’t been reallocated yet. These are sectors the drive is having difficulty reading.
- Uncorrectable Errors: Sectors that couldn’t be read even after error correction. If this value is above 0, treat it as urgent.
- Spin Retry Count (HDDs): How many times the drive’s motor has failed to reach operating speed and had to retry.
- Reallocated Event Count: The total number of sector reallocation events.
A “Caution” status in CrystalDiskInfo means the drive has crossed a threshold on one or more attributes. A “Bad” status means it has failed significantly. Either status warrants backing up immediately and replacing the drive soon.
Important: SMART data is useful but not infallible. Some drives fail suddenly despite showing “Good” SMART status, and some drives show “Caution” for years without failing. SMART is an indicator, not a guarantee.
Sign 6: The Drive Takes Longer to Become Ready
At startup, you may notice the computer takes longer than it used to before the desktop appears, or before files are accessible after a restart. If this delay is increasing over time, it can indicate the drive is taking longer to reach operating speed (HDDs) or to pass its self-tests at power-on.
What to Do If You Notice These Signs
Back up immediately. Every sign above is a prompt to back up, not to investigate first. Connect an external drive, copy your important files, and verify the copy before doing anything else.
Get the drive assessed. Bring the machine in for a PC health check — we check SMART data, run stress tests, and give you a clear assessment of how close the drive is to failure and whether replacement is urgent.
Don’t ignore it. A drive showing early warning signs that continues to be used will eventually fail. The data recovery cost for a failed drive is always higher than the cost of a planned upgrade on a drive that’s still working.
If you’ve already missed the warning signs and the drive has failed, contact us for a data recovery assessment. The sooner you bring it in after failure, the better the odds.
Our Putney workshop handles both preventive assessment and data recovery for all drive types. Call 020 7610 0500 or contact us.