Windows – How to change default background windows color

Your school's IT administrators are using either group policy or a third party program to restrict what you can do with your background.

I'd say that's a smart policy for them to implement, considering what many high school students might choose to use as their background when they have access to the web or USB flash drives. (I'm assuming high school based on the age in your profile).

Trying to find a way around this is equivalent to defying the administration's decisions, so you're probably safest not trying to get around their rules. I've gotten into enough trouble doing things I obviously wasn't supposed to be doing, and now that I do some light IT work I see how some restrictions like these make everybody's lives easier.

Well, it is certainly possible, as the desktop modders on DeviantART have been doing it.

I would think that will need to use Resource Hacker (last beta version for x64) or similar resource editor, like XN Resource Editor and open shellstyle.dll. The bitmap that you will need to replace will be in there somewhere.