How to compress system files in Windows 10

When the media is full, it is not necessary to immediately delete files from it. Windows 10 hides a compression utility, allowing you to free up even a few gigabytes.

Regardless of the size of the hard drive or SSD, sooner or later they all overflow. It’s just a matter of time., when Windows warns, that the free space is coming to an end. In such cases, many users frantically delete files, trying to free up space. But there is another possibility: Microsoft has integrated a utility into Windows 10, compressing important system files at your request. Thanks to it, you will quickly free up several gigabytes with one command.

However, is it worth compressing system files? Many users now, probably, they will wonder, won’t it slow down the computer. Theoretically it is possible, since the operating system will have to unpack such information in a new way, when you need it. But in practice, during the tests, we did not reveal any significant differences. This is due to the, that a small file is faster, than large, it is loaded from the hard disk into RAM, where then it famously unpacks faster, as a rule, RAM. Thus, on most systems, compression can even lead to a slight acceleration.

Our experience shows, what is the utility Compact.exe helps to free up from two to four gigabytes of space. At first glance, this is not so much. But in cramped conditions, every byte counts. First of all, the owners of inexpensive laptops with modest memory win - for example, eMMCs (Embedded Multimedia Cards). Such media are often characterized by a volume of 64 GB, and sometimes only 32.

Compression by Compact.exe

Even when upgrading from Windows 8 to 8.1, Microsoft added WIMBoot (Windows Image Boot) to the system - a new installation mechanism, thanks to which the OS takes up less space on the hard disk. Usually, the installer unpacks all system files from the ‘Install.wim’ file recorded by the PC manufacturer and copies them to the system partition, at the same time, files in compressed format also remain in case of recovery. WIMBoot, in front of, does not decompress compressed files, and creates pointers to them. This allows you to free up several gigabytes of space, however, in this case, a lot of information accumulates quickly, useless for the OS. So, more and more PC manufacturers are storing useful and not very pre-installed applications in the ‘Install.wim’ file.

In this regard, in the ‘top ten’ Microsoft Corporation additionally worked out this, in principle, an excellent idea and supplemented the utility Compact.exe a function called Compact OS. It saves OS files in compressed form and works as on computers with UEFI firmware, so it is with the usual BIOS Setup. The advantage of this approach is that, that it is easier for Windows Update to replace or delete individual system files. This feature not only saves space, but also cares about, so that the packaging and unpacking processes take less time.
Utility Compact.exe it can also be found in earlier versions of Windows. There it can be used, for example, to compress individual files and folders in NTFS partitions. But only the new Compact OS tool, implemented by Microsoft in Windows 10, it is capable of performing the system file archiving described above.

How to do it

Figuring out the memory allocation

To find out after all the procedures, how much space have you freed up, first, check the current distribution of data on the disk by the Windows 10 system. To do this, press the ‘Win I’ keys to open the ‘Parameters’ window. Here, go to the ‘System’ category and click on the ‘Storage’ line in the left column. The line under the item ‘This computer’ will tell, how much disk space is used by the OS. Write down the amount of space occupied on a piece of paper. As you can see in the screenshot above, 27.4 GB were used on the test computer before compression.

Opening the command line

To archive Windows 10 system files, run the ‘Command Prompt’ with administrator rights. To do this, right-click on the Windows icon in the lower left corner of the Desktop. In the context menu, select the option ‘Command Prompt (Administrator)’ and to the User Account Control security request, answer ‘Yes’.

Checking the archiving status

Things happen, that the manufacturer of your computer or Windows 10 activates compression by default, but in practice, this is extremely rare. Use the ‘compact /q’ command to find out the archiving status. You will get information not only about the number of compressed files, but also their ratio. The value of ‘1.0 to 1′ indicates that, that compression is not active yet. After entering the command ‘compact /Compact OS:query’ you will find out, why Windows has decided in favor of automatic compression or against it. You can safely ignore the advice to refuse compression, since its advantages in most cases outweigh the disadvantages.

Archiving system files

Run the Windows system file compression itself using the command ‘compact/CompactOS:always’. The computer will be busy packing for a few minutes. When using an SSD, it will take no more than three minutes. After that you will find out, how many files have been compressed and what the new archiving ratio looks like. In our case, the figure 1,7 was obtained. What is it more, the stronger the compression.

Finding out the amount of freed space

Follow the steps of the first paragraph of the manual again and compare the values from the ‘My Computer’ section with those previously recorded. So you will find out, how much space is available. In our case, it was about 2.7 GB.

Restoring the previous state

If, despite expectations, the feeling does not leave you, that compressing system files slowed down the computer, you can easily return everything to its previous state. To do this, enter the command ‘compact /CompactOS:never’. The process will also take a few minutes. After that, compression will be canceled