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Compress your OS Drive, 2019

Did You Check Disk Cleanup before Compressing the OS Drive?

Should You Need to Compress Your OS Drive for the installed Windows 10?

Like most Windows users, you may use Disk Cleanup to free up C drive space when the drive is running out.

On the Disk Cleanup window, you are required to check the items in the “Files to delete” list. In this list, you may find the item Compress your OS Drive.

You may want to select this item as you see the number on the right side of this item. You can indeed get lots of free space to C drive by checking to Compress your OS drive. But this is not as much as wise.

To explain why it is not recommended to check to Compress your OS drive, I have gathered four questions from Google related to this Disk Cleanup item.

Q 1: What is Compress your OS drive?

This is a new option that shows up in the February 2019 Windows Updates. It is not a kind of file.

Q 2: What does Compress your OS drive do?

If you check to Compress your OS drive, your files on the C drive will be compressed and you will see two blue arrows on every file.

Q 3: Is it safe to use Compress your OS drive?

It is safe! This option will not delete any files on your hard drive, so you do not worry about data loss.

Q 4: Should you compress your OS drive? Can I delete Compress your OS drive?

It's not recommended that you check to Compress your OS drive to free up disk space.

The reasons are that the files in C drive are compressed, and it needs time to decompress these files when your Windows OS calls them. After using them, it also takes time to compress these files again. This is time-and-power-consuming and may slow down your computer (check other reasons for a slow network).

How to Decompress Your OS Drive?

If you have freed up your C drive by checking to Compress your OS drive, you can follow the tutorial on restoring your OS drive to its previous state:
  • Open File Explorer, find C drive, and right-click it. Select the Properties option in the right-click menu.

  • Navigate to the General tab, and then un-check the Compress this drive to save disk space box. Click the Apply and OK button to confirm and execute the changes. You need to wait for about ten or more minutes (the time depends on how many files and folders you have), and it will be completed.
Considering that you may be in the dilemma that your C drive is running out, we offer you some ways of freeing up C drive in the following content. You can try any of them.

Free up C Drive Space by Removing Files

Removing files is also helpful when your C drive is running out. Apart from deleting the temporary files, you can also try deleting the enormous and unnecessary data or moving data to another location.

Delete Temporary Files via Disk Cleanup:
  • Click This PC on your desktop and then select the Properties option after tight-clicking the C drive.

  • Click the Disk Cleanup button and then check the files you won’t need in the new window.
Remove Large Files from C Drive:

To find large files saved on your C drive with ease, you can refer to the methods mentioned in the following recommended article. Furthermore, it also shows you what large files you can delete without any potential damage.

How to Find Large Files Taking up Hard Drive Space on Windows 10

You may find the hibernate file taking up ample space on your C drive if you have enabled the Hibernate mode. This file is created by OS when the computer goes into Hibernate mode. You can directly delete the hibernation file if you don’t need the Hibernate mode anymore or reduce the size of the hibernation file to remain this mode on your computer.

Move Files to Another Location:

If there are lots of pictures, audios, and videos on C drive, you can move them to another location to free up space.
  • Open File Explorer, select C drive, and then choose the files you want to move.

  • Go to the Home tab on the ribbon. Select Move to and then choose a location.

  • Select the target location from the list and then select Move.

Free up C Drive Space by Enlarging This Drive

Apart from removing files from the C drive, you can also try enlarging the space of the C drive. After expanding the C drive, your C drive has enough free space, and your computer can run faster than before. Now, let’s see how to modify the size of the C drive.

Step 1: Download MiniTool Partition Wizard, install it, and then launch it to get its main interface.

Step 2: Highlight C drive in the Disk Map and then click the Extend Partition feature, or right-click the partition to call out the Extend feature.

Step 3: Select one partition or the unallocated space on the system disk to take free space from it, and then move the bar to the left or right side to decide how much free space you want to add in your C drive. After that, click the OK button.

Step 4: On the main interface of MiniTool Partition Wizard, hit the Apply button to execute all changes.

To learn about something related to Compact OS (similar to Compress your OS drive) or more ways to free up C drive, please click here.


This post comes to an end. Please note that it's not recommended to compress your OS drive.

The compression will slow down your PC performance. When your drive space is running out, you can try other ways to get free space

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Kumar Bhanushali