After a reboot, I get back into my desktop and windows 8 forgets my wallpaper. I am greeted with a black screen everytime. WTH? I am running the full TechNet version. Clean install.
No problem for me running the Windows 8 Enterprise Evaluation! I use my MS Account with that and it were even taken the same Desktop Wallpaper I run on my Windows 7 Ultimate also with my MS Account! In my unactivated Pro version/installation I was change the Wallpaper and that works well. For that I was using an Windows 7 Theme Wallpaper.
The wallpaper setting works fine for me but whenever explorer crashes the tray icon settings of some programs are changed.Also I have scheduled taskmgr to run at startup.After crash the changes I made in taskmgr are gone.
May you should set a new Restore Point after changes are done. I do such for years already before and after changes in Vista and Windows 7 Ultimate. Just for to be sure that I could easy go back if any problems coming up.
I also have this problem. I have to use default windows 8 theme and wait it to sync with my account. Now you can use any wallpapers.