The original Bing Wallpaper is an open-source application which sets your wallpaper as Bing's image of the day, then runs in the background, offers an image-related search, a forced update feature and more.
Some people might need all this, but it seemed like overkill to us. We suspect most people will like the wallpaper-setting, but simply don't need yet another background process and system tray icon.
As it's an open-source project, we downloaded the code, stripped out the system tray and startup bits, leaving only the core wallpaper function.
The end result is BingWallpaperOnce.exe. Run this, it downloads Bing's image of the day, sets it as your wallpaper, and exits immediately. No notifications, no UI, no extras at all.
Add the program to your startup folder and it'll update the wallpaper every time you reboot. Or create a scheduled task to run it once a day, maybe.
Please note: all the credit belongs to the original author, we've done nothing more than remove lots of his hard work. It's also possible we've removed too much and introduced a bug, so if you run into problems, try the original instead.