Can I search my entire computer reliably?

Hi -

Is there an MS add-on or even a free 3rd party search tool?

I just want a simple, basic search tool that will search all local harddrives for a file. (like search on XP) - Preferably without indexinganything - I don't mind having to wait a little longer because I don'tfrequently use search, but when I do need to use it, I need to know to thatit is looking EVERYWHERE on my machine.

And I need to feel confident that if search tells me "0 files found" thenthe file is not on my computer. Search on Vista cannot do this (Or I can'tfigure out how to make Vista do this)

Any suggestions?