Question Is my C: drive dying? CrystalDiskInfo says "Caution"

Feb 26, 2019
Been having some slow downs, difficult restart times, and high disk usage spikes. After a crash ("Unexpected_Store_Exception") I decided to check on it with CrystalDiskInfo and here are my results:

I'm a bit worried because I do not have a back up drive available. If it's failing like I fear, approximately how long do I have? Is there anything I can do for it in the meantime?

Thanks in advance for the help!
It is best to use the drives manufactures testing software to determine the health of the drive. You can use SeaTools if need be. A drive can fail at any moment so when you have a chance, use this set up.

Basically you want:

3 copies of any data you don't want to lose.
2 different mediums it's stored on (so 2 different drives in your computer, for example).
1 copy kept offsite, to prevent against disaster.

In the mean time use a cloud backup.
Feb 26, 2019
Thanks all, though I don't understand what exactly has gone wrong with my drive..

I don't have cloud storage available either so I'm trying to buy a replacement ASAP. I've never replaced a laptop hard drive before though so I'm not sure what to look for. I have a Dell Inspiron 7559 and I don't know what to shop for. Would something like this be applicable? And are there any concerns about the replacement process I should be aware of?
spinning drives will fail eventually, with some at 3 years, some at 10 years, some semi-gracefully, some catastrophically....

A small 2.5" HDD would likely work, but, I'd look for a 500 GB or 1 TB SSD on sale for barely more money...(the whole laptop will seem much faster afterward!)

On a potentially problematic level, since the system is OEM/pre-built, how will we get the OS and data cloned over to it with sectors already failing?

A full fresh reinstall to a different drive is rarely easy, as your product key is linked/associated with a Dell, and, simply making new media creation from MS and reinstalling can be an issue when I attempted as much with a failing HP All-in-One...(they seem to want you to get your restore media from Dell which is rarely free....)

Do you have recovery media that perhaps came with the laptop? (A recovery partition contained on a failing drive is not quite as useful as we'd like in this scenario, and really only allows recovery/recreation of said partitions on same drive...)

We will hope it can clone with Macrium Reflect, AOMEI Backupper, or Acronis....
Reactions: Raivaryn
The drive is not dead. No need to exaggerate.
It has 856 pending sectors (hex 358).
Pending sector means, the drive could not read it for some reason. But this doesn't necessary mean the sector is bad. Pending status can be resolved by overwriting the sector. Then it either gets cleared or relocated.

You can do resolving of pending sectors with mhdd (scan with relocate on).
Reactions: Raivaryn
Thanks all, though I don't understand what exactly has gone wrong with my drive..

I don't have cloud storage available either so I'm trying to buy a replacement ASAP. I've never replaced a laptop hard drive before though so I'm not sure what to look for.
Well, the #1 priority is to backup your important data. The symptoms you've listed suggest the drive is in the process of dying, it is just a matter of time. Since you don't have a backup drive, dump it to cloud storage, any flash drives you have lying around, bring the laptop to a friend's house and dump it onto his computer temporarily. Don't use this laptop except to copy important data off it.

Using another computer, sign up for a Google account (gmail is probably the easiest). That will give you 15 GB of free cloud storage on Google Drive. It will also give you unlimited cloud storage of photos up to 2048x2048 resolution via Google Photos. You can opt to downsize your photos to make them fit in free storage. Not as good as the originals, but shrunken photos are better than non. It also gives you unlimited storage of videos, though I'm unsure what the size restrictions are. I think it's up to 1080p and 15 minutes (per video).

If you subscribe to Amazon Prime, then you have Prime Photos which gives you unlimited cloud storage of photos of any size and resolution.

If you subscribe to Office 365, it includes 1 TB of cloud storage in Microsoft OneDrive.

What's going on is that reading and writing data to a hard drive is kind of a black art. The magnetic fields used to hold data are extremely unreliable. A massive amount of error correction is used to make it reliable (like how you can scratch up a CD or DVD and it still plays fine). But occasionally a portion of the data surface just becomes so bad that the drive can't reliably read or write data to it.

When the error correction fails to yield the original data on a read, the sector is marked as pending. That just means that at the next opportunity, the drive will try to write new data to the sector, and try to read it back. If this succeeds, then it assumes the problem was a temporary glitch (maybe the problem data wasn't written well). It removes the sector from the pending list and carries on. So the yellow pending sector count could go back to green.

If the new data also cannot be read back, then the drive tries again several more times. Eventually it decides the sector is completely unusable. These failures are common enough that all drives ship with several thousand or several tens of thousands of so-called reserve sectors. These are unused sectors of the disk held in reserve just for problems like this. The drive alters its firmware, mapping out the bad sector, and replacing it with a reserve sector. From there on out, every time the drive tries to access the bad sector, it uses the reserve sector instead.

That's what the unrecoverable sector count is measuring. The drive only has so many reserve sectors. And when it's used a lot of them, that status indicator will move to yellow. There is no fix for this - it can never become green again. But since these types of failures are normal in an aging drive, usually you can use the unrecoverable sector count as a measure of how much life your drive has left. (It's not necessarily 1 sector = 1 count either. Each manufacturer uses a different way of measuring how many reserve sectors have been used.)

Unfortunately, there are are two ways sectors can become unusable. One is through normal aging and wear and tear. These are expected and nothing to be concerned about. The yellow unrecoverable sector count just tells you you need to start thinking about replacing the drive.

The second way is that the drive is beginning to suffer catastrophic failure. Maybe a bearing is failing and the platters are wobbling, making it impossible for the read/write heads to align consistently. Maybe some debris has gotten inside or broken off, and is now bouncing around, scraping off data every time it hits the platter. In this case, the drive will experience a rapid increase in the number of pending and unrecoverable sectors, before ultimately dying.

Your symptoms (slowdowns, long restart times, disk usage spikes, and crashes) suggest you're suffering the second type of failure. If it were normal aging, you'd suffer a single slowdown (when the drive tried to read the problem sector). And after it reallocated the bad sector, the drive would function normally again. Because you're experiencing consistent and repeating problems, that indicates lots of sectors are going bad simultaneously, which means your disk is almost certainly in the process of self destructing.

You have no way to know how much longer it's going to last, so it's best to spend whatever remaining time it has copying data off of it, starting with your most important data first. Run the drive as little as possible, as the longer you use it, the closer you get to its eventual death. Since you're going to replace the drive anyway, rather than try to boot off of the dying drive, I'd suggest removing it from the laptop and installing it in a desktop computer to attempt backing up your data. The SATA data and power connectors are the same for a 2.5" drive as they are for a 3.5" drive.


Reactions: Raivaryn
Feb 26, 2019
@Solandri Thank you so much for the explanation! I really appreciate you taking the time. This definitely helps me out, and I've managed to back up my most important files on a borrowed external HD. I'm also saving to some of the clouds you suggested.

@mdd1963 Thank you for the tips. I do think I've shifted my purchase to a hybrid drive that suits my needs and budget. Could you explain a bit more about how cloning works? I've never had to transfer an OS before and I'm not sure how (or what I need) to do it between two internals.

I was also reading that Windows might still activate?/install?/boot? for me after installing the new drive, no transfer needed. I can't find specifics though so I'm not sure what validity that holds. I don't even know if I could activate it, since I'm not sure how my digital license works.

EDIT: I've used my external to create a backup system image. Will this secure my Windows installation for the new drive? Is this effectively cloning? How will I transfer to the new drive?
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If it's Windows 10, then your license is tied to the CPU/motherboard. Changing the drive should not require activation. (I say "should" because I haven't bought a Dell in a while so dunno if their OEM version of Windows is different.)

By "system image" I assume you mean the one created by Windows' backup tool? Yes that should be sufficient. You will need to download the Windows 10 installer onto a USB flash drive though (it will wipe everything off the flash drive). After you install the new drive in the laptop, boot off the flash drive as if you were going to install Windows. During the install process, there will be an option to restore a system image. Point it to the image on the external drive, tell it to restore that, and cross your fingers.

I'd still prefer a full disk image clone or image though. The Windows backup tool tends to be all or nothing. If it encounters an error, it tends to bomb out without letting you restore anything. A disk image using something like Macrium Reflect will let you access individual files in the backup.

That said, since you'll still have the original drive (even though it's not working reliably), worst case you can just use Macrium Reflect or Minitools Partition Wizard to simply clone the old drive to the new one on another computer. There's no need to make a disk image right now if you've backed up your important data and have a system backup. The old drive isn't going anywhere.


Dec 31, 2016
Did you use the disk check built into the BIOS? Some pc's have a check built into the BIOS. This will give you the most accurate info. If something is wrong there, you should buy a new drive. If the device is still under warranty, ask for a replacement. You can also try this, but since it says unfixable I'm not expecting it to work:
  1. Open file explorer.
  2. Right click the C: drive and go to properties and then click on tools on the top.
  3. Click check under the tab 'Error checking'.
I'd recommend to buy a new drive anyway, anything you do to fix it, will be temporary. So, just buy a new drive to be sure it will work.
Edit: I see it's an HDD and not a SSD. You should open up the system and check if the drive is still in it's normal place and not moving around too much. You can clean it from the inside if you want, but if you touch one wrong thing, it can break the whole things, since HDD's are very sensitive.