I find Wise Jet Search very fast and very useful. However, it gives choice to search only from whole drives, like "C", "D" etc. It is fast enough, but, may bring unwanted results.
I would appreciate if it shows further tree structure within a drive and allow the user, if he/she wishes do, to search a particular or multiple folders within the Drive. For example: We usually would like too search "My Documents", "My Pictures" etc. folders only and have no interest in searching program folders.