Complete Guide to Compact OS: How to Enable Compression on Windows and Save Space

Compact OS is a built-in function of Windows that allows compressing system files to save disk space. This solution is particularly useful for those who own a PC with a small SSD, such as budget notebooks or Windows tablets with limited storage capacity (64-128 GB).

The compression is permanent but reversible and occurs transparently, without noticeable slowdowns during system use. Windows automatically manages file decompression when necessary, ensuring smooth operation.

This function is ideal for those who want to optimize disk space without having to delete important files or applications. Thanks to Compact OS, it is possible to recover several gigabytes of space without compromising system performance.

The solution is compatible with both BIOS and UEFI systems and does not require user configuration changes. For those who prefer a graphical interface, there is a third-party application called CompactGUI that leverages the same capabilities of Compact OS.

Prerequisites

• Hardware: A PC with a small SSD (e.g., 64-128 GB)
• Software: Windows 10 operating system or later version
• Administrative access: Administrator privileges to execute commands from the prompt

PROCEDURE: Enabling Compact OS on Windows

By following this guide, you will obtain additional space on your SSD by compressing Windows system files without compromising performance.

• Open the Windows Start menu.
• Right-click on "Terminal" (or "Command Prompt" depending on the version of Windows).
• Select "Run as administrator".
• In the command prompt, type the following command to check if compression is already active: Compact.exe /CompactOS:query
• If you want to enable compression, type the following command: Compact.exe /CompactOS:always

If you prefer a graphical interface, you can use CompactGUI, a free application that leverages the same features of Compact OS.

VERIFICATION AND TROUBLESHOOTING: How to test if it works and what to do if it fails

At the end of this guide, you will be able to verify the correct operation of Compact OS and solve any problems during activation.

Verification of operation

• Open the command prompt with elevated privileges (right-click on the Start menu, then "Terminal as administrator").
• Type the command Compact.exe /CompactOS:query to check if the system is already using compression.
• If the command returns "Compression state: Always", compression is active. If it returns "Compression state: Never", compression is not active.

Troubleshooting

• If the command Compact.exe /CompactOS:always does not work, make sure you have started the command prompt as administrator.
• If the system seems to slow down after enabling Compact OS, try disabling compression with the command Compact.exe /CompactOS:never and check if the problems persist.
• If you need further information, consult the official Microsoft documentation.

At the end of this guide, you will have learned how to enable and manage the Compact OS function of Windows to optimize the disk space of your PC.

• You have discovered that Compact OS compresses system files transparently, reducing clutter without affecting performance.
• You have learned the fundamental commands to enable, disable, and check the status of compression.
• You have known CompactGUI, a graphical application that simplifies the use of Compact OS.
• You have understood that this function is particularly useful for devices with limited storage space.

To put into practice what you have learned, open the command prompt as administrator and experiment with the Compact.exe commands. If you prefer a graphical interface, download and install CompactGUI.

If you have a small SSD, try measuring the space recovered before and after enabling Compact OS. The results might surprise you!