Can't add a custom wallpaper folder.. WHY???

Hi my friends.. i've a really worst problem..

in the windows 7 panel to customize wallpaper.. i can choose only the default wallpaper that stored in windows7 wallpaper folder.. if click over browse button, and choose an alternative folder.. and click ok.. anything happened.. how if i click over cancel instead ok..

is the first time that happened.. and tried to format and reinstall windows.. but nothing changed..

the only method to change background wallpaper with one custom.. is open a preview of that file in explorer.. and then with a right click over the preview.. choose use it how desktop wallpaper..

it change.. and in the panel there is a new browse in the menu.. Windows Photo Viewer, that is linked to:

C:\Users\XXX\AppData\Local\Microsoft\Windows Photo Viewer ...

how this??

how can solve??

thanks a lot

The default folder for wallpaper is c:\windows\web\wallpaper.

Just copy your images there...

yeah.. i know.. but in the past.. i choose a simple custom folder where get my custom backround.. i have ultimate version of 7...