[omg_ponies]

This has not been true for some time. You can continue to use un-activated Win10 installs: https://en.wikipedia.org/wiki/Microsoft_Product_Activation#A...

You just can't change the wallpaper away from black, and there is a notice displayed on it.

[snazz]

You can change the wallpaper by right-clicking on an image file, just not through the personalization preferences.