I have just installed V16.0.3, when I select to update to V16.0.4 I get a message " It was not possible to install the files on your computer"  "Please verify that all programs are closed and restart the update" (See attached)

I have closed all programs restarted Windows 8.1, tried the update again and receive the message as above.

Fixed...I have just noticed while I had no noticable programs running, I saw OneDrive was updating/Syncing, I paused the OneDrive sync, sucessfully rerun the V16 update