C drive full Win10

How to fix Windows 10 C: drive full issue?

The price keep coming down, so the hard drive is getting bigger. Nowadays, many Windows 10 computers use hard disk with TBs of storage. However, many people feedback Windows 10 C drive is getting full without any reasons. Actually, many types of files continuously write into C drive every day, especially for Windows Updates, which eat up free space very quickly. Another reason why C drive full is common in Windows 10 is because many people use Solid-State Drive (SSD) for Operating System and applications. SSD is efficient to improve computer performance but it is still quite expensive, the smaller disk storage, the higher possibility to run out of space. When C drive is full in Windows 10, try to fix as fast as possible, otherwise, Operating System runs much slower, stuck, reboot unexpectedly or even crash. In this article, I’ll introduce how to fix Windows 10 C drive full issue with ease.

C drive full Win10

What is taking up space in C?

There are so many files that may take up space in C drive. C drive full on Windows 10 could be caused by Windows or 3r-party applications.


It could be divided into 3 types of files:

1. Windows Updates

Due to technical bugs, security threat and other reasons, Windows automatically download and install Updates continuously. This is the top factor that cause C drive getting full, because there will be many and large Update files accumulating in C drive if you do not free up space.

2. Windows service

Windows service such as Paging File, Hibernation, Backup and Recycle Bin could take up several GBs space of each.

3. Other Windows files

Other files such as temporary, cache and logs are with small size but could be in large amount.


1. Installation 

The more applications you install, the less free space left. Some applications also eat up free space quickly, such as: Games, Projects, Graphic and Videos.

2. Default output path

Some people like to use default settings for installation and daily usage. It is not a good habit, you’d better install applications to other volume such as D, and change the default output path to other volumes that is in large size.

How to fix C drive full in Windows 10?

1. The fastest way to fix Windows 10 low disk space is resizing partitions. Transfer free space from other volume and add into C drive, and then there would be plenty of free space in C drive, so Windows 10 will back to the right way. This step is important for the computer that use SSD as system disk and the ones that C drive was created too small.

2. If you do not cleanup disk and change the way using your computer, C drive becomes full sooner or later even if you expand C drive to large size.

Expand volume to increase C drive free space

To resize and extend volume in Windows 10, there is free partition manager software for you, such as NIUBI Partition Editor Free Edition.

Step 1: Downloadto install, right click D drive and select Resize/Move Volume. In the pop-up window, drag left border rightwards to shrink D.

Shrink D

Drag to shrink

Click OK and it will back to the main window, the free space shrank from D will be changed to Unallocated behind C drive.

Unallocated created

Step 2: Right click C drive and select “Resize/Move Volume” again. In the pop-up window, drag the right border rightwards to hold the Unallocated space.

Extend C drive

Step 3: Click OK, C drive free space was increased. Click Apply on top left to execute, done.

C drive extended

If there is not enough free space in volume D, simply get from any other volumes in the same disk, just need an additional step to move partition.

Disk Cleanup to free up space

Disk Cleanup is used to delete unnecessary files to reclaim disk space. Follow the steps:

1. Right click Windows on bottom left corner and select System, switch to Storage. If Storage sense is turned off, I suggest you turn it on.

Disk cleanup

2. Click Change how we free up space, select files and click Clean now.

Select files

You may also use traditional way: open File Explorer, right click C drive, click Properties and then Disk Cleanup.

Disk Cleanup

Select the files you want to delete.
Select files

Clean up system files
Clean system files

Change the way running your computer

To permanently solve C drive full in Windows 10, besides the steps above, you’d better change the way running your computer, too.

  1. Run Windows Cleanup as monthly maintenance utility.
  2. Install new applications to other volume instead of C drive.
  3. Change the output path to volumes in large size.

In Windows 10, there is new storage setting which is useful. Right click Windows on bottom left corner and select System, switch to Storage. Click Change where new content is saved.

Change location

Change the default settings and click Apply.

Change settings

In Summary

When C drive is getting full in Windows 10, shrink other volume and add free space to C drive. Cleanup to free up space and change default storage settings.

Windows 10 C drive full solution
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