EXT4/BTRFS and Windows

Overview

The file system used by the Steam Deck to store and play Steam games is EXT4. When you insert a microSD card in the Steam Deck, it will ask to format it – and when it does, it will be formatted to EXT4. Steam Deck can also use BTRFS formatted SD cards as well, but that isn’t the default.

File System Compatibility

Windows uses the NTFS file system and is compatible with others such as FAT32 and exFAT. While Steam Deck can use these file systems to read and write data (like emulators, ROMS and BIOS) but Steam Deck insists that you use an EXT4 (preferred apparently) or BTRFS formatted microSD cards and drives.

Windows cannot see either EXT4 or BTRFS out of the box. So, it is impossible to effectively move “Steam Games” from Windows to your microSD card without a tool that can read and write (formatting would be helpful). You need a tool to do this – and Desk Drive Manager does not provide this out of the box.

Tools

There are a few tools to use; some paid, some free – some are super easy to use and others require a good deal of work to set up.

EXT4

Deck Drive Manager was designed specifically to use Linux File Systems for Windows from Paragon Software. This tool works on all modern versions of Windows (including Windows 11). It offers read, write and formatting capabilities for EXT4 – making it a perfect solution. There is a $20 one time charge for this product – and a trial version is available.

This app will also READ BTRFS file system disks, but not write to them.

If you’re a Windows 11 user and have some power user skills, you may be able to use Windows Subsystem for Linux (WSL) to mount your EXT4 drives. You can learn more about this here. Choppy waters ahead…

BTRFS

The accepted free solution appears to be the WinBTRFS Driver by maharmstone. This allows read/write and formatting of the BTRFS file system in Windows. However, I tried it under Windows 11 and saw the first blue screen of death I’ve seen in a long time. Supposedly it works very well under Windows 10 though – and it is free and fairly simple to install.