Drives not appearing on desktop

I believe that CreateDesktop is set to false. Try running defaults write com.apple.finder CreateDesktop -bool YES in Terminal (unless you are on Mountain Lion or below, in which case the command is defaults write com.apple.Finder CreateDesktop -bool YES), followed by killall Finder. You should be able to view items on and drag items to your Desktop now, including drives.

If these kind of Finder problems are user specific, you can fix them by removing your Finder preference files in your Library.

The files you want to delete (backup) are:

• com.apple.sidebarlists.plist
• com.apple.finder.plist

You can find them in ~/Library/Preferences/ (Home -> Library -> Preferences). Go to Finder, press commandshiftG and paste ~/Library/Preferences/

Now you need to relaunch Finder (logout/login, or reboot, or commandaltesc)