Using tinker tool I unhide hidden folders and then when I clicked on relaunch finder, my desktop would not load. I think its because I had a USB External HD Connected when I clicked on relaunch finder.

So basically what's happened is that my desktop does not load, no HD icon, no folders nothing. However I can access the folders that were on my desktop by going to finder from the dock and then clicking and desktop in the sidebar. Also I can not drag any folders or files to my desktop from finder. For example I can not drag a file from my documents folder to my desktop but I can drag folders to the desktop folder in finder.

What I've done so far is
- clean my user and system cache - using the app main menu
- went to disk utility and verified disk permissions - nothing found
- cleaned corrupted preferences files using main menu

Am I going to have to reinstall Mac OS X
Does anyone know how to fix this?

Thanks for any help