Can't change Win7 wallpaper

Hey guys, I havn't found a solution that works for me after hours of googling.

So since yesterday I can't change my wallpaper anymore. When I select one of the standart themes the style of the bars changes, but not the wallpaper.

Also my login-background which I changed the way Maks Hacks described it, is set to standart. I checked the files and everything is still the way I left it. It should work...but doesn't somehow...


I had a similar problem. I just did a system restore to the previous day, tried again and it worked.

hmm I could do that, but I changed some stuff and don't want to loose that. Nothing that should provoke an error like this though.

still thanks!