There are several symptoms that you may start to suffer from on your PC when your hard drive has bad sectors: from extreme slowness while processing files stored on the hard drive, to strange noises in the drive, to crashes and crashing. file corruption. If you start to notice any of these symptoms, it is possible that your hard drive is starting to die due to too many bad sectors, but don’t worry as it is still possible to fix them to bring the problem back. disc to relative normality.
What are bad sectors and why do they occur?
Internally and in order to better manage information, mechanical hard drives group the information they hold into sectors made up of a certain number of bits. These sectors are created so that, let’s repeat that internally, some sort of map or index can be created so that the disk knows where each bit of information is and is able to send the lyre to the appropriate sector for it. be able to read or write information.
When you try to read or write to a sector and for some reason the head is not able to do so, the reader reports it as faulty and rejects it (this means that the next times it will not try not even read or write to this sector). There are two types of bad sectors and the causes that produce them are multiple, but we will try to explain it in the simplest way possible:
- Physical issues: usually caused by shocks (dropping your hard drive to the ground for example) or serious head errors (called head crashes) in which the platter has been physically damaged and, as a result, certain sectors have been left permanently inaccessible. This type of bad sector cannot be fixed, although we can mitigate the problem by having the hard drive permanently delete the affected sectors to avoid errors.
- Logical problems: They are caused by disk read or write failure, which can be caused, for example, by sudden power failure while the hard disk was writing data. In some cases, they can also be caused by errors or data corruption in which the sector has disappeared from the index we talked about a moment ago. In these cases, the problems can be completely repaired.
How to tell if your hard drive has bad sectors
In the image we have placed above these lines, you can see the inside of a hard drive that has suffered a “head crash”, and in which we can clearly see that the head has completely damaged the surface of the hard drive. tray, making it virtually unusable. If this is your case, you will notice that the hard drive is making a series of strange noises, such as scratches or scrapes, and obviously it is not working properly.
To find out if your hard drive has bad sectors, the best thing to do is to use the tools that Windows contains for that, because they are simple to use and really very efficient. We are talking about utility CHKDSK Which we’ve talked about many times before, a tool precisely designed to detect and repair almost any kind of problem you might have in your storage drives (not just hard drives but also SSDs or even USB drives).
To do this, right click on the Start button and select the option “Command Prompt (Administrator)”. In the window that opens, you must execute (type and then press ENTER) the following command:
chkdsk x: / F (where x is the drive letter assigned to the hard drive; you can check its handwriting by simply going to “This Computer” in Windows).
If you run the command directly from Windows, you will see a screen similar to the one above, in which the operating system tells us that the unit is in use and cannot be scanned, we prompting to unmount the volume (something that only It will appear in the event that the hard drive to be scanned is not where you installed the operating system) or if you restart the computer and CHKDSK runs automatically at the next start. In all cases, press the Y on your keyboard, then press ENTER to accept.
The process consists of three phases, in which the system first scans the drive and then tries to repair any errors it finds (the third phase is just a check). The process can take a long time depending on the capacity of your hard drive and the number of errors it finds, but if the errors are fixable, this tool will take care of everything and you won’t have to do anything.
Another way to check if your hard drive has bad sectors is also built into Windows. Go to “This Computer”, right click on the problematic drive and click on “Properties”. Go to the Tools tab and you will see something like this:
Click on the Check button and the system will scan the hard drive for problems, errors and bad sectors. If there is a problem, the software itself will offer to try to fix it automatically without you having to do anything else.
Can bad sectors of hard drive be repaired?
As we mentioned, both with CHKDSK and with the Windows Check tool, you can detect and try to repair bad sectors on your hard drive, but neither of these tools are completely foolproof (and the problem may not be repaired if the damage is physical, as you were told at the beginning) so the hard drive may not be in good condition anyway.
If the problems are not physical but logical and the previous tools could not fix the problem, another more direct method is to perform a low level formatting of unity, a process that will delete all information It contains (so back up data first) as it literally resets all hard drive bits one by one including sector allocation and index.
This is a pretty drastic way to fix hard drive with bad sectors, but if the bad sector issues cannot be fixed, they will be ignored in the new sector assignment and so you can continue to use the hard drive after the process. Of course, if the number of bad sectors on the disk is large enough, you will see that its maximum capacity will have been reduced because, literally, it will have fewer usable sectors.