The Windows 7 Search is definitely world's better than XP...to the point I actually use it, and find it useful, without the need for third-party apps.
I don't know why people bitch and complain about it so much...considering how easy it is to use, even on external drives. In the main explorer window, you can enter the term, or part of the term in the upper right, and have it find what you are looking for. You don't even have to right-click, or move off of that screen. Aside form searching by ESP....it doesn't get any easier than that...and yes, you can search by partial terms just fine.