To try the easiest thing first, Click Here
to open a Kelly's Korner page.
Scroll down to line 187 and in the right-hand column, click on "Restore Luna Theme" to download a zip file. You may have to right click it and left click "Save Target As" or, if using Firefox, "Save link as."
Once you have it downloaded, unzip it to the C:\WINDOWS\Resources\Themes folder. Then see if things work in Display Properties.
Even if this is not the problem, it won't hurt to do it. All it does is replace a possibly damaged Luna theme folder with an undamaged copy.