Windows 7: USB write protection error

since i updated my windows 7 ultimate 64bit,i have lost the writing method on it,i can't even see delete in the drop down menu when right click on the drive..when i try to format it..it says it is write protected..

i have searched a lot about it,everyone says it's the registry issue.there are posts that can fix it.but that doesn;'t work for me...i guess formatting my windows drive is the last solution.
the usbs are working fine on my other computers,but not on this one.i am very much fed up with this ! my system restore option was turned off,now i can't undo to my happy windows 7



any solutions? thanks.