Probably the king of the hill here is Probe - you would need, I think, to run this in a DOS box within Windoze (although old 486s and the like are easy to find at hamfests and computer fairs). The other 2 I know of are RadioMax (which, according to John Catalano in a recent MT article, works just fine under XP) and ScannerWare. I don't have a good link for ScannerWear; the last I heard it was available from the R10 Yahoo group, but needs a registration key (with the software no longer supported, I would imagine someone has hacked it by now).
The links for all 3 can be found on the Strong Signals
software page. Just click on the blue 'software' and you'll be taken there.
73s Mike