The search bar found in your Windows Explorer window offers an amazing amount of flexibility for performing advanced searches on files and folders on your computer. Unfortunately the interface for performing advanced searches is very limited, so you need to learn a few commands.
Here are a few examples of advanced searches:
Match files or folders begining with the word "Help"
name:~<"Help"
Match only folders begining with the word "Help"
name:~<"Help" type:folder
Match only folders containing the letters "Help"
name:~="Help" type:folder
Match any folder NOT matching the word "Help"
name:<>"Help" type:folder
Here is a quick article for understanding the basics:
http://windows.microsoft.com/en-us/windows7/advanced-tips-for-searching-in-windows
Here is a complete list of the available parameters:
http://msdn.microsoft.com/en-us/library/aa965711%28VS.85%29.aspx
And an article discussing the parameters:
http://blogs.technet.com/b/danstolts/archive/2011/06/08/taming-windows-7-search-syntax-knowing-the-syntax-makes-all-the-difference.aspx