dnGREP - dnGrep allows you to search across files with easy-to-read results.
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
AstroGrep - AstroGrep is A Microsoft Windows GUI File Searching (grep) utility.
SMF – Search my Files - SMF - Search my Files v13 is the fastest duplicate files finder and a multi-dimensional - file searcher, - file copier / mover, - file deleter / eraser, - and
Agent Ransack - Agent Ransack is a tool for finding files and information on your hard drive fast and efficiently.
Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.