How to Fix Windows 11 Low Disk Space on C Drive

by John, Updated on: November 6, 2021

Many Windows 10 users encountered the problem that C drive runs low on disk space after update to Windows 11. If Windows 11 is pre-installed in your laptop/desktop/tablet, you'll encounter the same problem someday. In that case, C drive is changed to be red in Windows 11 File Explorer. It is annoying when C drive is running low disk space, because computer becomes much slower, stuck or even crash. In this article, I'll introduce how to fix Windows 11 low disk space on C drive fast and easily.

Why is C drive low disk space after update to Windows 11

Before updating to Windows 11, most of Windows 10 computers have running for a long time. There are already large amount of files saved to C drive. If you installed all programs to system partition by default, C drive is filling up quickly. It'll become full even if you created it as large as 100GB.

When updating to Windows 11, there are additional files saved to C drive. In general, it consumes about 5GB to 10GB free space. When you receive low disk space alert in Windows 11 computer, you'd better fix this issue as fast as possible. Otherwise, system runs slower, computer stuck or even crash.

How to fix Windows 11 low disk space issue

No matter C drive runs low disk space after updating to Windows 11 or in pre-installed Windows 11 computer, you can solve this problem with 3 steps. Of course there are other methods on the Internet, but these 3 methods are most effective.

Method 1 - remove junk files from C drive

When system C: drive runs low on disk space in Windows 11 laptop/desktop/tablet, the first thing you should do is cleaning up disk to remove junk and unnecessary files. If you just update from Windows 10 and never clean up C drive before, you may reclaim over 10GB free space. To free up disk space in Windows 11, there's a native Disk Cleanup tool. It is easy to use, runs fast. The most important, it is able to remove most of junk files safely. You don't need to worry about system damage.

How to fix Windows 11 low disk space on C drive issue by cleaning up disk:

  1. Press Windows and R together on your keyboard, type cleanmgr and press Enter.
  2. C: drive is selected by default, to clean up other drive, you can select it in the drop-down list, then click OK.
  3. Click the check-box in the front of the files that you want to remove. If you are not familiar with them, click it and read corresponding description on the bottom.
  4. Confirm this deletion in the pop-up window.
  5. If C drive run low disk space after updating to Windows 11, repeat from step 1 and click "Clean up system files" in step 3.

Method 2 - add more free space to C drive

The second and most important step is adding space to C drive from other partition. Some people have tried to clean up disk before but Windows 11 low disk space alert pops up again in a short time. Because new junk files are keeping saved to C drive, if you cannot get over 20GB free space, of course C drive will becomes full again. Therefore, you'd better expand C drive as large as possible.

With safe partition software, you can shrink a partition to release free space, and then add to C drive. In this way, operating system, programs and anything else (except partition size) keeps the same with before. To accomplish this task, NIUBI Partition Editor has free edition for Windows 11/10/8/7/Vista/XP home computer users.

How to fix C drive low disk space in Windows 11 by adding free space:

  1. Download NIUBI free edition, right click the adjacent partition D (or E) and select "Resize/Move Volume" option, drag left border towards right in the pop-up window. Then Unallocated space is made on the left.
  2. Right click C: drive and run "Resize/Move Volume" again, drag right border towards right to combine this Unallocated space.
  3. Click Apply on top left to take effect.
  • If there's not enough free space in the adjacent partition, you can shrink nonadjacent partition on the same disk.
  • If there's no other partition or not enough free space on the same disk, you can clone system disk to larger one and extend C drive with extra disk space.

How to add free space to C drive from other partition:

Windows 11

How to add more space to C drive with a larger disk:

Windows 11

Method 3 - move programs and files out from C drive

Many people install programs to C drive with default setting, in fact, it is not a good habit. The more programs you installed, the less free space left. In addition, some programs will output large files in the installation directory. You'd better install to a separate partition, don't throw everything to system partition C. What to do if you've installed programs to C drive? In Windows 11 computer, you can move programs (installed from Store) to other partition without reinstalling. Follow the steps below:

  1. Press Windows + R keys, paste the command ms-settings:appsfeatures and press Enter.
  2. Click an app or game.
  3. Click the Move button.
  4. Select the new location from the drop-down list.
  5. Click the Move button.
  6. Repeat step 2 to move more items.

To the programs that installed with traditional method, change the default output path to a larger partition. The programs for video, project and game will output large files. In addition, you'd better change the download path of Internet browser to other partition, too. To the files in original download folder, you may delete them or move to the new folder.

Again, the most important step is extending C drive as large as possible.