My gadgets have just gone missing too all of a sudden. I'll for sure try out the advice above but grr! My desktop looks so naked!
EDIT: To further irritate me, they're not back after disabling/rebooting/enabling/rebooting them via 'Enable/Disable Windows FEatures'.
Also on the second boot up before i got to the desktop it told me my copy of Windows wasn't genuine and i should purchase (!) a legit copy. When i did get to the desktop and checked in 'System' my copy is activated and verified as genuine. WTH?!
I can go into the gadget box and drag them out but they just don't appear. Also, obviously related, i cannot create a shortcut on the desktop or drag a file to it. Currently scanning my drive for errors...