Hi, I got a Windows 8 tablet for work purposes. One restriction set on it was that you couldn't change the background of the start screen as they wanted a consistent image accross all devices. So, I found my way around it by replacing the lock.jpg file in the Windows folder. I managed to change it. Now I would like to change it back to the default. So, I replaced the file again back to the default. Now it isn't updating back to the old one. Even though I replaced the file, it still shows up as the one I set before. Any suggestions on how to fix this or get it to work? Thanks.