No icons and taskbar but the wallpaper

Hello,
i hve a problem with my pc everytime i switch it on no icons and wallpaper appears but only the desktop wallpaper.And then after that it displays a dialog box that says "windows explorer has encounted a problem and needs to close" and afta i hit the dont send button it jst remain as it is no progress afterwards.I tried the ctrl-alt-del key combination but it does not respond.how could i fix this problem plz help