1. A method for identifying unmatched registry entries, comprising: scanning a file system and discovering software; collecting first attributes of the discovered software; collecting native registry entries; and comparing the first attributes of the discovered software against second attributes of the collected native registry entries based on a filtering rule, thereby grouping the native registry entries into two groups, wherein one group represents matched registry entries and the other group represents unmatched registry entries, thereby identifying unmatched registry entries as unequivocal entries for further software discovery.