Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
Agent Ransack - Agent Ransack is a tool for finding files and information on your hard drive fast and efficiently.
dnGREP - dnGrep allows you to search across files with easy-to-read results.
dtsearch - dtSearch - The Smart Choice for Text Retrieval since 1991.
SearchMyFiles - Alternative to the standard Search For Files And Folders module of Windows. Duplicates search is also supported.