LanHunt is a lan based search engine, which enable users to download and look for content shared on local area network. LanHunt is fast, typically giving results in seconds. Database update is required only once from the inbuilt updater. Supports parallel downloads, parallel searching, direct "open location" feature, filetype based narrowing and much more.
Check out this one 'Lobyy' here on sourceforge, with many advanced features.
no trouble to install and run, works nicely.