Lets face it, Windows has some 'lovely' background images for various applications but some are just too 'dated'!
This one may be fairly insignificant but you can change it, if you wish, easily using a PNG image of your choice with the help of:
Resource Hacker
Default:

Carefully follow the procedure found here:
Tip
This one may be fairly insignificant but you can change it, if you wish, easily using a PNG image of your choice with the help of:
Resource Hacker
Default:

Carefully follow the procedure found here:

How to Modify System Files Using Resource Hacker in Windows - AskVG