How to Clear Hard Drive Space on Windows 10

There’s a lot of fluff that you don’t really need.

Photo by Bruce Hong on Unsplash

There are several reasons why you might want to clear extra space on your computer’s hard drive. Maybe it’s getting a bit full, and you need space to install a program. Or maybe the computer has slowed to a crawl, which in some cases can be due to an overfull drive (see the notes in the next section about when this is and isn’t the case). Or maybe you’re just a bit obsessive about keeping things tidy. No matter what your reason, there are some simple ways to clear lots of space without touching the things you actually need to keep. And even if you do need to delete your own files, there are smarter ways to do it than tediously digging through them all.

Do you really need to clear space at all?

Before you start going through any of these instructions, make sure that you need to clear space at all. If your system is running well, and you’re not almost out of space, then you likely don’t need to worry about how much is on your hard drive.

One of the most common reasons that people try to clear hard drive space is that they think it will help speed up a sluggish computer; but generally speaking, that’s not the case. Your hard drive isn’t like the trunk of your car, where more stuff in it equals more weight, which takes more power to move. It’s more like your garage. The stuff in there takes up space, and you can put it in the car (open a file) when you need it, but it doesn’t impact the performance.

BUT!

In one particular case, hard drive usage can be a performance issue. If your hard drive gets very, very full — north of 90% full — that can make your computer run extremely slow. This happens because normally Windows uses some of the free hard drive space to swap files around, and create temporary files — and if Windows doesn’t have enough space to work with, it takes much longer to get things done.

So before you start working through this guide, check and see how much of your hard drive you’re using.

1. Open File Explorer — Click the Start button in the lower-right corner, type “File Explorer” in the search field, and click on File Explorer.
2. Display the Drives — On the left side of the File Explorer window, click “This PC”. Your hard drive should appear in the window, usually marked as “OS C:”, and it will show how much of the drive is in use, complete with a handy bar.
3. Check the Storage — If the bar is less than 90% of the way full, then your storage probably isn’t impacting your computer’s speed. If the bar is very high, and especially if it’s red, then you definitely need to clear some space.

*Disclaimer: It’s important to make sure you have any important files backed up before doing any system maintenance. I’ve used the techniques below to clean up dozens of systems without issue, but it’s your responsibility to ensure that you don’t accidentally lose important files.*

Turning Off Hibernation

One of the easiest ways to clear significant space on many computers is to turn off hibernation, an ultra-low-power mode built into Windows. Why does this help? Hibernation uses an often very large, hidden file called “hiberfile.sys”. When you disable hibernation and reboot the computer, this file is cleared, which frees up a chunk of space.

I like to start with this step because it’s easy to do, which is important if the system has gotten painfully slow, and it quickly frees up a large amount of space, so doing the rest of the procedures will go smoother. Also, most people don’t really need hibernation turned on, as the standard sleep mode is sufficient to save power when the system is idle.

1. Run Command Prompt as Adminstrator — Click the Start Button, and type “Command Prompt” in the search bar. Right-click “Command Prompt” in the results, and click “Run as Administrator”. Click “Yes” on the confirmation window that pops up.
2. Enter the Disable Hibernation Command — This will open a black Command Prompt window. Type the following, exactly as written, including the spaces and without the quotes: “powercfg.exe /hibernate off”. Then press Enter on your keyboard.
3. Close Command Prompt and Reboot — You’ll get a new prompt below the line you typed. Now you can close the Command Prompt window, and reboot your computer.
4. Check the Storage — When the computer reboots, check the hard drive usage using the steps in the section above. It should have dropped at least a couple of GB, and maybe as much as 12GB!

Clear Unneeded System Files with Disk Cleanup

Windows 10 has a built-in tool for cleaning itself up, and it’s a reliable way to clear out system files that feels much safer than manually deleting data that you’re not familiar with. It’s also easy to run, and can clear lots of space with one click.

1. Open Disk Cleanup as Administrator — Click the Start Button in the lower-left corner. Type “Disk Cleanup” in the search. Right-click Disk Cleanup in the results, and choose “Run as Administrator”. This will unlock some extra options that we’ll need.
2. Select Your Main Hard Drive — A window labeled Disk Cleanup: Drive Selection will pop up. It should have your main hard drive, “OS (C:)” selected already. If not, choose the correct drive from the drop-down menu. Click “Ok”.
3. Choose Items to Delete — A Disk Cleanup for *drive name* window will pop up. Scroll through the list of items available, and look for ones that are taking up lots of space, paying special attention to whether the amounts are in KB (kilobytes, very small), MB (megabytes, pretty small), or GB (gigabytes, large). If an item is under 200MB, you can usually leave it. Mainly, you want to get rid of the things that are taking up multiple GB of space — the main culprits are usually temporary files, old Windows Update files, and old OS files if you upgraded this computer from Windows 7. Check the boxes of the items you want to get rid of.
   Important Note: There are a couple of items here that you should take extra care with. “Downloads” is a folder where most files that you download are stored by default. Much of what you have in there is probably old program installers, and PDF files that you looked at once, but you may have files there that you want to keep. If you’re at all unsure, leave that item unchecked. Likewise . . . and it pains me to say this . . . don’t check the Recycle Bin item unless your sure that there’s nothing in it that you need. Of course, the Recycle Bin is supposed to be for things you want to throw away, but I have absolutely encountered people who use it as just another folder.
4. Delete the Files — Once you’ve checked the boxes of all the items you want to get rid of, click Ok. A confirmation window will pop up. Click Delete Files if you’re sure you’re ready. A Disk Cleanup progress bar window will pop up. Step away and let the process run. If you’re deleting many GB of data, this could take quite a while. Be patient and let it run.
5. Reboot — Once the Disk Cleanup progress bar goes away, reboot your computer.

Find the Files/Folders Hogging Space with WinDirStat

After following the last couple of sections, you may be all set for storage space. If that’s the case, feel free to stop here. But if you do need to clear more space, including going through your personal files, there’s a great, free utility for that job called WinDirStat.

WinDirStat is a powerful way to dig down and find exactly what is eating up your hard drive space, and clean it up quickly. You definitely need to be careful when using this tool. If you don’t know what a file or folder is, then don’t delete it. Windows has lots of components, and it’s not always obvious whether they’re important.

You can download WinDirStat from the official website. Run the installer, then open the program. A small window will come up where you can choose which drive to work on, and in most cases you’ll want to choose Individual Drives, select OS (C:), and click Ok.

WinDirStat will now show all of the folders on your hard drive, and you’ll see the sizes tick up as little Pac-Men chomp back and forth. Depending on the size and speed of your hard drive, this may take a while to complete. Be patient, even if the window shows “Not Responding.”

Once WinDirStat is done examining your data, you’ll have a list of all the folders on your hard drive, and probably some big colorful blobs along the bottom — the colorful part is a visualizer for what’s on your hard drive. I don’t find the visualization particularly helpful, though, so I get rid of it by going to the Treemap menu and unchecking Show Treemap.

Now take a look at the list of folders that WinDirStat shows. It helpfully shows the amount of space that each folder is using, plus it sorts the list from largest to smallest size. And here’s the cool part: if you expand one of those folders by clicking the + next to it, you’ll be able to see all the folders inside of that one, which are also sorted largest to smallest. So if you do have a forgotten large video file somewhere, for instance, you can easily continue expanding those large folders until you dig down and find it.

For anything you find in WinDirStat that you are confident that it’s okay to delete, just right-click the file, and choose Delete(to Recycle Bin). When you’re done, open your Recycle Bin, make extra sure that you want to lose all those files forever, and then click the button along the top to empty it.

Conclusion

So there you have it; three fairly easy ways to free up space on your hard drive, without a lot of time wasted in picking through small files that aren’t even the real issue. And you can come back to these steps any time you find that storage is getting low.

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