How To Check If A Hard Drive Is Failing

Check if your hard drive is failing using the free program HD Tune. ‘Do you have a backup’ are words that nobody wants to hear, particularly if it is too late to create one. Of all the components in a computer the hard drive is the most vital because it stores your important data.

We typically see modern hard drives failing after just 3 – 4 years (quicker in laptops that have had a hard life) but even a new drive can fail within weeks if you’re unlucky. A hard drive may fail ‘nicely’, slowing down or losing a few files as parts of it become unreadable – this may cause errors but it may still be possible to recover data from it.

Or a drive may fail the ‘tough’ way – total failure, sometimes accompanied by a regular clicking sound (known in the trade as the click of death), making it impossible to retrieve any data from the drive unless willing to spend hundreds of dollars to attempt retrieval. A drive that has been failing for some time is very likely to end up becoming a total failure eventually.

We review how to test if a hard drive is failing below – if possible, always backup any important data beforehand – testing works it hard and makes it hotter so if it is already failing, testing may finish it off completely…

Check A Hard Drive Within Windows – If your computer will not load into Windows skip to Step 4.

We will use the free program HD Tune – you can download it from here (second option down is the free HD Tune, not the commercial HD Tune Pro version). Install the program and run the HDtune.exe program. If you have more than 1 hard drive in your computer, check that the correct one is listed at the top of the HD Tune Utility or select the correct one from the drop down menu.

Step 1 – Check The Health of the Drive. Click on the ‘Health’ tab – if you see no details skip to Step 2 (some drives do not provide information here). An example is shown below:


Heath Check

The health status at the bottom should be OK and all items in the list should have a status of OK. If the Reallocated Sector Count is highlighted in yellow then the drive is likely failing.(Note: some drives may show a different item highlighted in yellow but with a status of OK – this may be due to the way the drive is recognized and is not always a problem).

Step 2 – Check For Bad Sectors. A bad sector is like a scratch on a CD – if any data was stored in that sector of the hard drive it can no longer be recovered. Bad sectors are a definite sign of failure – they may also slow the drive down and cause crashes/prevent Windows loading.

Click the ‘Error Scan’ tab to scan for bad sectors. Ticking the ‘Quick Scan’ box will make the test run much quicker but is not as thorough as a full scan (so you may miss warning signs that your drive is failing). We recommend running a full scan by leaving the Quick Scan box unticked.

Click Start to run the scan – a full scan may take an hour or more on a large drive. An example in progress is shown below:


Scanning for Bad Sectors

When completed, every block should be green – a red block means the drive has a bad sector and is damaged.

Step 3 – Check The Speed of the Drive. On the ‘Benchmark’ tab click Start to test the speed which may take a few minutes – example below of a test in progress:


Speed Test

Check the graph – it is normal for it to go gradually downwards as the test progresses. Some peaks and troughs are normal if Windows is installed on it but the troughs should not be almost to the bottom of the scale.

The minimum speed is measured in MB/sec and should not be less than 25% of the maximum speed – if the minimum or maximum is less than 10MB/sec the drive may be failing and the computer will be extremely slow. Alternatively, the drive may be stuck in an extremely slow mode called PIO – see our article how to fix drives stuck in PIO mode.

Step 4 – The Drive Is Failing or Windows Won’t Load Up. If you have not already done it – back up your documents and files now. Before replacing your hard drive or returning it under warranty, search for diagnostic software from the hard drive manufacturer to provide a conclusive check on the drive – a useful list of manufacturers and their diagnostic tools can be found at Tacktech.

Tip: If you don’t know the hard drive manufacturer do a Google search for the model number of the hard drive as shown by HD Tune (e.g. in Step 2 ours showed as ST3500320AS – a quick search of Google reveals that it is made by Seagate).

Follow the instructions given by the manufacturer to download and run their diagnostic tests. Most offer their software in the form of an ISO file you can use even if you cannot get into Windows – if unsure what to do with ISO files see our article on how to burn an ISO image file to CD.

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10 Responses to: "How To Check If A Hard Drive Is Failing"

  1. Braden says:

    I have a 1 year old HP Touch Smart laptop with the Samsung 1 TB HDD. I am running Windows 8.1 update. The drive is partitioned. I keep all my data on the logical partition. Lately when I right click on any file stored with File Explorer, File explorer crashes all the time.

    I’ve re-installed 8 a few times and the same thing always happens. The files are not corrupt since I can copy them and they work fine on my other computer, also running 8.1. I’ve run the manufacturers HD diag software on it and no errors. I also tried HD Sentinel, no errors and then HD Tune 5.X. HD Tune shows a spin up retry count threshold warning. And the count has gone up. Just for test purposes I tested a spare Samsung drive with the same specs as this one in an external HD dock. HD Tune shows no errors on the external.

    The laptop has a 2 year extended warranty from Best Buy. The HD is still flaky in my books. The last time I ran the manufacturers diags, it couldn’t see the hard drive at all until I re-opened the software twice in succession under Windows. The boot version of the diags never sees the hard drive. In all fairness, the laptop always boots into Windows fine, no problems there. HD Tune shows only the spin-up retry count threshold warning. Should I believe HD Tune?

    • Roy says:

      @Braden – doubt it’s a hard drive problem as the manufacturer’s own test (and others) pass. HD Tune is only giving a warning and it’s likely that is actually being caused by the Explorer crashes – hence why your external dock does not have the same errors, because it’s not subject to the same crashes…

      Most likely cause of your right click crashes is a bad (Explorer) shell extension – each time you have reinstalled W8 you have probably reinstalled all the same drivers/updates/programs – if one of them is bad/out of date then you’ll keep getting the same problem…

      Try using ShellExView from to disable non-microsoft shell extensions one at a time until you (hopefully) find the culprit that causes right click crashes. That website has a great link to an article explaining how to use it – see the pink “right-click is slow or weird…” link top right of that page.

      If you find one extension to be the cause, either leave it disabled or look for an updated version of that program.

  2. Becci says:

    Thanks for posting this, I had a PC build half a year ago and it was fine. Recently started playing up though, making weird noises, not booting up without the boot disk, random freezes and getting stuck on the check disk. Took it back to the shop once and they said there was no problems but I’ve run HD Tune and got 1 yellow warning and 13 red boxes (the scan is still running, not even halfway through yet). Definitely taking it back to the shop again and showing them pictures of the scan results!

    • Roy says:

      @Becci – Each red block represents a bad sector i.e. a damaged part of the drive – physical damage which can’t be fixed. If the drive is under warranty, just one red block should be enough to request a replacement – your other symptoms match that of a failing drive too.

      Do try to backup your important documents/data first – a good shop should offer to transfer your data to a replacement hard drive but some don’t (or forget) and once they have sent the bad hard drive back to the manufacturer then it would be too late.

  3. Roy says:

    Hi, if you don’t have at least 2GB RAM you may get temporary freezes. In the Benchmark test in HDTune if the graph (speed) has massive drops to <5 MB/s the hard drive (or motherboard controller) is likely faulty.

    Do a full series of RAM tests – Memtest86+ and Windows Memory Diagnostic are good

    Also check temperatures for overheating

    Test power supply if you have a tester. Random freezes can be a pain to pin down unless they are very frequent or you can replace parts e.g. swap power supply/graphics card/RAM with known good ones to test for a week or so

    If there is an intermittent motherboard fault you’re not likely to be able to diagnose it unless you have replaced/tested all the main components already :-(

  4. mackenya says:

    I have done a complete check with the HD Tools Pro program. Everything appears to be OK. I am running Windows 7 and keep getting random monitor “freezes”. I did a complete re-install of Windows 7 etc. and everything was fine for a few days and then the same problem started again. Any advice you can give me on the best way forward would be appreciated..

  5. Lesley Poole says:

    I downloaded hd tune pro ran the check the health drive and got a yellow warning. I am currently running the error scan and am half way through with 4 red blocks up to now. What do I do now to fix the problem.

    • Roy says:

      Hi Lesley, each red block represents a bad sector i.e. a damaged part of the drive. This is physical damage which can’t be fixed (and may get worse) – it may also result in the computer being very slow or freezing/crashing.

      If the drive is under warranty, just one red block should be enough to request a replacement. If it isn’t, the only permanent ‘fix’ is to replace the faulty drive with a new one.

      Either way, do backup your important documents/data asap so if it fails completely (or Windows won’t load) you can restore your data onto a new hard drive/computer.

  6. admin says:

    Unfortunately you will not always get a warning if a drive is going to die soon – sometimes they just fail suddenly and completely. However, if you run the tests and it is failing then it likely has not long left to go.

    If yours passed all the tests, that is good news but it does not mean the drive is safe forever. Always keep an up to date backup of your important documents/data so if the worst happens you can restore onto a new drive/computer.

  7. BernieMac says:

    I tested my drive and it looks ok, does that mean it will not die – for how long? Do you always get a warning if it is dying soon?