Hello, everyone! I'm new to here and I'm new to Windows Vista, I found a problem of my Vista Home Premium. At the beginning I set a png format picture as my desktop, I found the quality of the desktop was far worse than the original png file. I suspect Windows Vista convert it into a bad quality jpg file then set it as desktop, so I convert the png file to a "quality 100"-jpg file, but the desktop display result is as the same as the former png file. As you can see the two pictures which were taken from my computer in the attachments. Is there any solution about this? Thank you!