How to Fix 100% Disk Usage Error in Windows 10

Last Updated: September 30, 2016

Windows, like any other operating system, is prone to errors, and sometimes, it’s a little on the abundant side. As the OS has matured over the years, the number of common errors has reduced, but unfortunately, some new ones have started popping up. One very specific error that we see on Windows 10, and that initiated with Windows 8 and 8.1, is the 100% Disk Usage Error. Effectively, what this does is scale your hard disk usage to full, resulting in everything slowing down to a crawl and a very frustrated end user. Luckily, there’s a fix for that, and in this post, we’ll discuss how you can fix the 100% Disk Usage error on Windows 10 and below.

Note: For the purpose of this article, we’ll be specifically discussing Windows 10, although the solutions can apply to previous versions of Windows as well.

What causes the 100% Disk Usage Error

While there can be a variety of reasons behind it, generally, this error is caused by some Windows services like Superfetch, Prefetch, BITS and Windows Search. While these factors are the usual suspects, they’re not the sole ones; there can be a variety of others, including malware, Flash and even a really old and slow hard drive.

Determining if you have the 100% Disk Usage Error

Determining that you actually are facing this error is easy yet important, because you don’t want to go around making changes to your computer for nothing.

While the slowness of your machine will be a fairly good indicator (along with a constantly on hard disk light), you can verify the issue by pulling up the Task Manager in Windows 10 (just hit Start and start typing Task Manager, or press CTRL + Shift + Esc). In the Processes tab, the Disk column will be showing 100% if the error exists; if not, you’ll see something similar to the screenshot below.


Fixing the 100% Disk Usage Error

Assuming your machine is suffering from this issue, here’s how you can fix it:

1. Do a virus scan of your Windows 10 computer

This might seem like a general, common sense advice, yet it’s crucial that you perform this action as your first remedy in this case. Many a times a malware infection can be the culprit and you can do whatever else you want, it won’t fix the issue. Better to be sure beforehand in this case. You can use any good antivirus software for this purpose.

2. Disable Windows 10 Superfetch service

Superfetch is one of those Windows services that will always have the potential of delivering a bittersweet user experience. The premise behind Superfetch is that Windows will learn from your usage habits and “guess” which applications/services you’re most likely to use next. Based on this prediction, the OS will cache those apps and programs to the RAM, so they’ll load faster. Now, in theory, that’s a fantastic concept, but unless you’re a robot that’s programmed to follow a particular routine, Superfetch’s predictions are bound to miss from time to time. And because the service is busy pulling all those predicted app files and data from your hard disk, you get the 100% Disk Usage error.

Disabling Superfetch is just like disabling any other Windows service. In Windows 10’s search, type Services and open the Services dialog. Within here, find the Superfetch service, and right-click to get to Properties. Here, Stop the service and in Startup type, make sure it says Disabled. Hit OK and restart your Windows 10 computer for good measure.


3. Disable Background Intelligent Transfer Service (BITS)

BITS is yet another Windows 10 service that’s supposed to be helpful but can turn out to be quite the opposite. The idea behind BITS is that when your computer is sitting idle, the bandwidth can be used for Windows Update, Windows Defender and the like. While it usually works just fine on newer machines, older hardware can actually suffer while BITS tries to decipher when the computer is actually idle.

Disabling BITS will be just like disabling the Superfetch service, except that in this case, you won’t disable the startup altogether; instead, you’ll opt for Manual.


4. Disable Windows Search

This is one of those “solutions” that I’d generally not recommend unless absolutely necessary. For quite some time now, Windows has had a very robust search function that indexes everything on your machine, making it easier to find files and all other content. While the feature is all great, one rather persistent bug has been the “search loop”, where a system running Windows will endlessly re-index files and folders over and over. One quick way to identify if this is the cause of 100% Disk Usage is very low CPU and Memory usage in Task Manager along side 100% Disk Usage.

The drill is again the same here: find Windows Search in Services, right-click for Properties and Stop the service while disabling the startup. If this was the culprit, you’ll see an immediate impact.


5. Disable Windows 10 Prefetch

Windows 10 also bundles a neat feature to complement Superfetch: Prefetch. While Superfetch caches data to RAM based on intelligent guessing, Prefetch works when you launch those applications. Essentially, Prefetch records information on files that are used by any given application, and then pulls those files to RAM to improve app loading times.

Because it’s again intelligent guessing by the OS here, there is a likelihood that the Prefetcher will miss. And it does. And when it does, disabling it remains your logical choice. However, Prefetch isn’t your standard Windows service and tweaking it required making changes to Windows Registry, which is why we recommend this as a very last-resort solution only.

To open the Registry Editor, type regedit in Windows 10 search bar and hit Enter. In the folder tree, navigate to the following location

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters


In the right side pane, you’ll see an entry for EnablePrefetcher. Double-click it and change the DWORD value from 3 (default) to 0 to completely disable the service. You may also put in 1 as the DWORD value, which will keep Prefetcher partially enabled but disabled for boot files.


Please note that you’ll need to restart your computer for all these changes to take effect.

6. Run CheckDisk

CheckDisk is one of the oldest command line tools at the disposal of Windows users, and one that’s usually helpful. This will come in handy if there’s a problem with the physical hard drive, the folder tree or anything of that nature with your Windows installation. The best approach towards running CheckDisk is to do so when your system reboots, so you’ll need to actually schedule for that. Luckily, that’s fairly easy.

Launch an elevated command prompt (type cmd in Windows 10 search bar, right-click and select “Run As Administrator”) and run the following command:

chkdsk /f’ /r C:

where C: will be replaced by whatever drive letter you’ve assigned to your Windows installation. You’ll see a message within command prompt that will ask you to confirm whether you’d like to run CheckDisk on next system reboot. Acknowledge with a Y, and restart your computer. CheckDisk might take some time to finish, but it can be very useful not just for 100% Disk Usage error but some other issues as well.

7. Disable Windows Tips

This one did not make sense to us, but a lot of people have reported that this did the trick for them. Windows 10 offers tips about the operating system from time to time, and disabling those seems to have helped mitigate the 100% Disk Usage error for a variety of people. We note this here because you won’t be losing much in disabling those tips, and it’s pretty easy to do. Just go to Settings, then to System and then Notification & Actions. Disable “Show me tips about Windows” in this list, and voila!


SEE ALSO: How to Fix High CPU/Memory Usage in Windows 10

When all else fails… and otherwise, too

While this concludes our list of suggestions for fixing 100% Disk Usage error, there’s one more thing that we’d recommend whether you have this error or not: upgrade to an SSD. They are the future, and for a reason; traditional hard drives can simply not compete with the performance of an SSD. They’re wicked fast, they’re far more reliable, you’re far less likely to ever face the disk usage error with an SSD, and they’ll make your whole computing experience a lot more pleasant. Invest in an SSD, and you’ll find it worth every dime you spent.

Well, that’s all from our side and we hope the aforementioned ways helped you fix the 100% disk usage error on your Windows PC. Do let us know if you have any doubts in the comments section below.


Aatif is a veteran tech blogger with a passion for gadgets and mobile apps. He describes himself as a "student of technology" and spends most of his money on getting the latest and greatest gadgets. He is also a diehard fan of science fiction, and enjoys casual photography in his free time.