In an attempt to fill a gap between fully automatic search/match programs and purely manual methods based on paper products, PCSIWIN has been developed a PC-based Search/Index program for extracting information from powder diffraction databases. The program provides adjustable search and match windows to account for experimental errors. Both Hanawalt and Fink search methods are incorporated: PCSIWIN is designed as a replacement for these paper based methods. We introduce a Goodness of Match (GOM) to describe the relative agreement between the experimental input data and selected patterns from the Powder Diffraction File (PDF). The relevance of the GOM is illustrated in several example problems. Multiphase samples can be treated on a phase-by-phase basis.