If your computer is running Windows 8.1 or Windows RT 8.1, the OneDrive desktop app is already built in. If you've updated Windows and aren't sure which OneDrive version you have or which version you need, see Which OneDrive app? For more information, see Sync files with OneDrive in Windows. OneDrive appears automatically in File Explorer and as a location to save files. If your computer uses Windows 10-OneDrive is built-in, so you shouldn't need to install the desktop app.