Should You Use "Disk Cleanup" to Compress Your OS Drive? The Answer Is Here [2024 Full Guide]

Introduction

Your operating system drive is running out of space, and you're wondering whether you should opt for a "Disk Cleanup" to compress your OS drive.

By compressing your drive, you can free up several gigabytes of space and get rid of those pesky disk-space warnings.

However, every time you access the compressed file and close it, it decompresses and compresses it again, putting a strain on your CPU and RAM.

Let's understand what compressing your operating system drive is and what it does.

#1 What does “compress your OS drive” mean?

The "Compress operating system drive" feature was added in a Windows update in February 2019. This feature was not available prior to that update.

This option can free up space on drive C.

If you'd like to know how to add space to the C drive, you can read the article below:

3 Ways to Increase C Drive Space in Windows 11/10/8/7

Is your C drive running out of space? How to increase C drive space for better computer performance? This page will guide you to easily expand C drive on Windows 11/10/8/7.

2. What does "Compress operating system drives" mean under Disk Cleanup?

"Compress operating system drive" is an option in the Disk Cleanup tool that compresses files on the drive to make them smaller, freeing up space on the drive.

You can find the “Compress operating system drives” option under the “Files to delete” section of Disk Cleanup.

When you choose to compress your operating system drive, all of the data on it will be rewritten by the compression algorithm, which will compress everything to create more space on your OS drive.

What happens if you compress your operating system drive?

Compressing files or disks to save disk space can free up some room, but it adds to the CPU's workload.

When you open a compressed file or drive, the CPU has to uncompress it first, and then recompress it when you close the file or drive. This is very CPU- and RAM-intensive.

After a while, your computer will slow down and become unresponsive after all the compressing and decompressing.

When and how to use Compact OS to free up disk space?

Compact OS is another new feature added to Windows 10. This feature will reduce the size of the operating system. In addition, you can run the OS from a compressed file.

The UEFI and BIOS-based firmware both support the Compact OS feature, which significantly shrinks the space that the operating system takes up, leaving more room for new apps.

Here's how to free up disk space by using a lightweight operating system:

Step 1: Click the "Start" button, then search for "Command Prompt."

Step 2: Now, right-click on it and select “Run as administrator” to open the Command Prompt with administrative privileges.

Step 3: In the Command Prompt window, type compact /compactos:always and press Enter.

Step 4: Wait a few minutes for the process to complete, and make sure not to turn off your computer while the update is in progress.

Should you use Compact OS to free up disk space? Probably not. While it can affect PC performance, the impact isn't as significant as with compressed OS drives.

There are other drawbacks to using Compact OS, however, such as the possibility of increased disk fragmentation.

Other ways to free up space in Disk Cleanup

There are many other ways to free up disk space without choosing “Compress operating system drive.” You can use third-party tools to create space, or you can manually delete files.

"Disk Cleanup" isn't the only solution for freeing up space when your disk is almost full. You can try other methods to create disk space for your operating system drive.

Method 1: Run a disk cleanup utility to clear and compress the operating system drive

Compressed files do save space on your PC, but they can also cause irreversible damage to it. Extracting a file to open it consumes a lot of RAM and CPU resources, and even your antivirus program might fail since it can't always scan inside compressed files for viruses and malware.

Partition Master is the best solution for the problem of lacking disk space.

With the Partition Master tool, you can create or delete partitions. If your OS drive is running out of storage space, you can delete unused partitions to free up more room for the OS drive.

You can also use this program to resize partitions without losing data. Or, use the "Extend" feature to expand a partition and make use of any available or unallocated space.

Partition Master is a free download with a host of features to meet all your disk space needs.

We will guide you on how to free up disk space with this software. You can follow these steps:

Option 1: Extend System C drive with unallocated space

1. Right-click on the System C drive and select "Resize/Move." 2. Drag the system partition to the unallocated space, adding it to the C drive. Then click "OK." 3. Click "Apply" and "Execute Task" to perform the operation and extend the C drive.

Option 2: Extend System C Drive with No Unallocated Space

1. Right-click on a large partition with ample space on the system disk and select "Allocate Space." 2. In the "Allocate space from (*) to" section, choose the system drive, then drag the end of System C to the unallocated space. Click "OK" to confirm. 3. Click "Perform Tasks" to view the pending operations, then click "Apply" to save the changes and extend the C drive.

0:00-0:26 Extend the system drive using unallocated space; 0:27-0:58 Extend the system drive without unallocated space.

Method 2: Free up and compress space on your OS drive by deleting files manually

Another way to free up disk space is to manually delete files.

1. Delete Temporary Files

Here are the steps to follow:

Step 1: Right-click on the "C" drive and select "Properties".

Step 2: In the Properties window, click on the "Disk Cleanup" button under the "General" tab.

Step 3: Select the file you want to delete from the list.

Select files

Delete Large Files from the Operating System Drive

Here's how to find and delete large files from your operating system drive:

Step 1: Press the "Win+R" keys and type control.exe in the Run dialog box.

Step 2: Type file in the search box on the Control Panel, then choose “File Explorer Options” and select “View.”

Step 3: Select Show hidden files, folders, and drives. Deselect the Hide protected operating system files (Recommended) checkbox.

Step 4: Click “Apply” and then “OK.”

5. You should now see a file called "hiberfil.sys" in the root directory of your system drive.

Step 6: Delete the hiberfil.sys file.

If Hibernate is enabled, the hibernation file can take up a lot of space. You can free up space on your system drive by deleting the hibernation file.

Manually deleting files can be risky, since you might accidentally delete important ones and damage your operating system. You may instead choose to download and use a third-party cleaner, since these are programmed to leave important files alone and only delete unimportant ones.

Frequently Asked Questions about "Disk Cleanup Compress OS": 1. What is Disk Cleanup Compress OS? Disk Cleanup Compress OS refers to a feature within the Disk Cleanup utility that compresses operating system files to save disk space. This typically includes temporary files, system logs, and old update files. 2. Why is it necessary to compress the operating system? Compressing the operating system can be useful when running low on hard drive space. It reduces the disk size by optimizing and compressing files. 3. How do I run Disk Cleanup Compress OS? In Windows, you can access it by following these steps: Start menu -> All Programs -> Accessories -> System Tools -> Disk Cleanup. Then, select your system drive in the Disk Cleanup dialog, which will calculate the available space and provide a compression option. 4. Does compressing the OS affect performance? There might be a slight impact on computer performance during the compression process as the system needs to work extra to read and write compressed files. However, once completed, the effect on daily use is usually minimal. 5. Are all files compressed? Not all files are compressed. The system intelligently selects which files can be safely compressed without affecting the operation of critical programs. 6. How do I decompress after compression? There's no need for manual decompression; the operating system automatically handles the compression and decompression of files as needed. 7. Is there a high risk of data loss? If executed correctly, the risk of data loss using Disk Cleanup Compress OS is relatively low. However, any file manipulation process carries a potential risk of data loss, so it's advisable to back up important files before proceeding. 8. Are there alternative disk cleanup tools? Yes, there are various third-party disk cleanup tools available, such as CCleaner, which offer similar functionality and sometimes more advanced features. However, exercise caution when using these tools and ensure they come from a trustworthy source.

There are a few more things you should know about disk cleanup.

1. What does Disk Cleanup do?

Disk Cleanup searches for files that can be deleted to free up space on the disk.

2. Should I defragment my SSD drive?

The answer is no. There's generally no need to compress your C drive, unless you're running out of space. In that case, it's better to avoid compressing the entire drive, since uncompressing files every time they're opened can be a CPU-intensive task that might degrade your computer's overall performance in the long run.

Why is my C drive full?

It could be that:

• Applications you've installed
• Files and settings related to your operating system
• Files saved to your desktop or in library folders, such as Photos, Videos, or Documents, that use space on drive C:

Conclusion

Compressing the hard drive can free up some space, but this is not recommended. Instead, move your files to another disk or drive.

You can also use a partitioning tool, such as the freely downloadable Partition Master, to create space on your system drive.