How to delete old Windows install files and free up drive space

Hard Drive
Hard Drive (Image credit: Windows Central)

When you update your PC from an existing Windows installation, the old files remain on your hard drive. They are saved there instead of being overwritten because something might go wrong during the update installation, or because you might want to roll your PC back to a previous installation if you aren't happy with the new stuff.

If, however, the update to Windows 10 goes smoothly, and you're sure you don't want to return to a previous version of Windows, you can delete those old installation files to free up space on your hard drive. This is especially important for anyone using a device with a smaller solid-state drive (SSD).

Although removing old Windows installation files won't harm your PC, it's always a good idea to back everything up in case something goes wrong. Once you're sure you're completely satisfied with the Creators Update, this guide can help free up space on your hard drive.

How to delete old Windows installation files

Removing old Windows installation files can't be done by simply selecting them and moving them to the Recycle Bin. You have to use Disk Cleanup, but luckily the process is simple and won't take long.

  1. Right-click the Start button.
  2. Click Search.
  3. Type Disk Cleanup.

  1. Right-click Disk Cleanup.
  2. Click Run as administrator.
  3. Click the dropdown arrow below Drives.

  1. Click the drive that holds your Windows installation. If you only have one drive in your PC, this selection window will not appear; your C: drive will automatically be selected.
  2. Click OK.

  1. Click the checkbox next to Previous Windows installation(s) so that a checkmark appears.
  2. Click the checkbox next to any other options to select or deselect whether or not they're also removed. You might also want to choose to remove the following options:
    • Temporary Windows installation files.
    • Windows upgrade log files.

  1. Click OK.
  2. Click Delete Files.

Once the old installation files are removed, you won't be able to roll back to a previous version of Windows. Unless you have a secondary backup that you can restore from, you'll have to do a clean install of Windows to return to a previous state. So make sure you're really ready before you remove the old files.

More resources

Don't forget to create a backup of your data whenever you can. To help, we created a guide featuring a bunch of different ways to accomplish this. If you'd like more information on the latest Windows 10 update, the Creators Update, be sure to check out our Senior Editor Zac Bowden's definitive review.

Cale Hunt
Senior Editor, Laptop Reviews

Cale Hunt is a Senior Editor at Windows Central. He focuses mainly on laptop reviews, news, and accessory coverage. He's been reviewing laptops and accessories full time since 2016, with hundreds of reviews published for Windows Central. He is an avid PC gamer and multi-platform user, and spends most of his time either tinkering with or writing about tech.

15 Comments
  • Delete your previous version of Windows (Source: Microsoft - https://binged.it/2pyUr0y)
    1. Go to settings.
    2. Select System > Storage > This PC and then scroll down the list and choose Temporary files.
    3. Under Remove temporary files, select the Previous version of Windows check box and then choose Remove files.
  • Exactly what I wanted to comment 😁 But you were faster 😉
  • Would you happen to know if there is a fast method for getting rid of windows.old on a drive that is no longer a boot drive (so it doesn't offer the clean system files option) other than manually overriding permission's and deleting folders?????  
  • When you open Disk Clean-up, you have to first select a button that says "Clean up system files", otherwise the "Old Installation Files" won't show in the list. Also, you if you have updated the OS then you can manually delete "Windows.old" from the C:\ drive but that may cause problems.
  • If you run Disk Cleanup as admin (as mentioned in the guide) you shouldn't have to click the "Clean up system files" button.
  • Removing previous installation is a must for many tablet users. So before proceeding, if you're missing any items from your desktop, folders, locally stored emails or pictures, this is where they'll be.
  • Hey everyone, out of topic but please reply this question. My pc used to boot in 10 seconds. I went on a 1 week vacation. After I returned, the pc takes at least 20 seconds to boot. I don't know why but the circle is spinning too many times. Any suggestions?
  • threat it with a hammer unless its faster
  • Install CCleaner, it lets you check which programs are being started when OS starts, there could be a recent program you installed like iTunes, Steam, or in my case I have a AMD Radeon software which is used to swith from discrete GPU to Intel Onboard graphics, so this software takes a lot of time to start.  With Ccleaner you can delete the programs you don't want to start when your computer starts.
  • Bring up "Task Manager" and look at "Start up" tab. It will show you apps that start automatically and the impact to performance.
  • once I use ccleaner for the removal of old windows installation. but when I switched on pc after switching it off, it never started and it said an error occurred and pc never started. I tried to recover using the back up on my hard drive it didn't worked. so at last I had to format my entire hard drive and installed windows with the dvd drive. so I hope this is the better way to free up the space.
  • Ccleaner can't remove your old windows installation, I know it because I have Ccleaner and no matter how hard you try it won't remove windows old binaries, you need to follow the article guide.
  • ccleaner has an option to clean the old windows installation. I have done it many times and it does clean. but sometime it creates a mess out of it like what I suffered.
  • This is very basic stuff going back to Windows 95. If someone does not know how to run the disk cleaner in Windows, they should use a Mac because they are too stupid to use a Windows PC. Lack of knowledge and training has always been the biggest cause of problems with PCs. You take a course to get a driver's licence but people will not take the time to actually learn a damn thing about their computer. If someone is that lazy, they should stick to an iPad or Android tablet.
  • How does one learn to use disk cleaner without being taught with something like this?