My Desktop&taskbar Is Gone!

I have vista home premium, all was going well until yesterdayThe PC will boot up normally, I can see everything icons, taskbar all boot up. Once it is all up and ready they dissapear! I can't even right click on desktop nothing happens! The only thing left on desktop is the gaget bar.The only way to get online to internet is by going through the "get more gagets online" part of the gaget bar.