SearchMyFiles - Alternative to the standard Search For Files And Folders module of Windows. Duplicates search is also supported.
dnGREP - dnGrep allows you to search across files with easy-to-read results.
FileSeek - FileSeek is an easy-to-use file search app that includes advanced functionality for power users!
AstroGrep - AstroGrep is A Microsoft Windows GUI File Searching (grep) utility.
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.