File access
File access and external storage
Because UWP apps are sandboxed, they do not freely roam the file system the way a desktop program does. By default an app only sees its own private folders. For an emulator, that is a problem, since your ROMs and BIOS files live outside those folders.
Broad file access
The UWP model offers a special broad file system access capability. When an app declares and is granted it, the app can read and write user-accessible locations, including attached USB drives. RetroArch must have this enabled before it can see ROM and BIOS folders, and you typically turn it on in the app's settings the first time you run it.
| Location | App access |
|---|---|
| App's own data folder | Always read and write |
| App install folder | Read only, never writable |
| USB and user folders | Only with broad file access enabled |
Where to put your files
The cleanest approach is a USB drive. Create clearly named folders such as roms and bios, copy your content over on a PC, then point the emulator at those folders once file access is granted. Keeping content on USB also sidesteps the 2 GB per-app cap entirely.
An app can never modify its own install directory. If something tries to save into the install folder it will silently fail, so always direct saves, states, and configs to the data folder or USB.