Cannot help you there sorry, but I feel like moaning about the 7 search
I have given up on trying to make the Windows 7 search work for me. It is just not flexible enough and seems to freak out if the file is not indexed. That is my only complaint about 7. I now use the search feature in Total Commander....much better
in the search bar it will return all the folders. You can sort them according to size, then. I can't convince it to search for folders with certain sizes of contents yet, though.