Some Windows 10 users have reported error 0x803F7003 while downloading and installing apps in Windows 10 Store. Error code of 0x803F7003 which is basically an error that does not let users download apps from the Windows 10 store. Once download, the app will moves to the download section of the Windows store app but fails to download. Below are how to fix Windows 10 store error 0X803F7003:
Step 1: Click Start button (or press the Windows key or in the Cortana search box) and type wsreset in search box.
Step 2: Right click on the app and select Run as administrator from the drop down menu to reset the cache of Windows Store.
Step 3: UAC (User Account Control) dialog will appears with confirmation that the cache has been reset when open the store app, and then click Yes to continue.
Step 4: Go to Windows 10 store and download the app again. Perform a reboot and then try to download the app again if same error shown.