I don't know what I did, but I lost the "show desktop" icon at the bottom. How can I get that back.

You can restore the Show Desktop feature to the Quick Launch area by doing this: Go to Quick Launch (C:\Windows\Application Data\Microsoft\Internet Explorer\Quick Launch). Create a new Text file using NotePad while in Quick Launch as follows:

[Shell]
Command=2
IconFile=explorer.exe,3
[Taskbar]
Command=ToggleDesktop

Save the file as SHOWDESKTOP.SCF. You should be back in business.

after you're done doing that,
right click on it and hit "create shortcut" grab the new shortcut and drag it into your quick launch tab!

haha...!! i did it!!
by my experience, don't use MS word to write this program =>
"Command=2
IconFile=explorer.exe,3
[Taskbar]
Command=ToggleDesktop "
cause it will save it to .doc word document, this really sucks, no matter how you try to change it, it won't go to scf file format! , so, just use accessories' notepade to write this program, then save it to C:\Windows\Application Data\Microsoft\Internet Explorer\Quick Launch, then you could yeil whatever loud you want ! hell ya !!! hooo hoo ~~~~ i did it , i did it, idid..... !!! ha!

you don't know how happt im, i did it in the well-firewall-protected county library, hack right in the protection read-only-section !, im really genius !!