Windows key does a few things like that. Some others off the top of my head:

Windows + F : Opens a search window (used to be F for Find before MS went all trendy and changed everything to "Search" - didn't change the shortcut though)
Windows + E : Opens an explorer window
Windows + U : Opens Utility Manager - Narrator/Magnifier etc
Windows + R : Opens a run command window

I think there are few others