If I were shipwrecked on a desert isle and could take only one software program with me, it would be Agent Ransack, hands down.

Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface. Quick file indexing. Quick searching. Minimal resource usage.

FileSearchy allows you to quickly search for files on your PC by content string, date, and size. Project has been abandoned.

Quickly search through large numbers of files on your PC or network using powerful text patterns to find exactly the information you want. Search and replace with plain text or regular expressions

Recoll is a desktop full-text search tool. Recoll finds keywords inside documents as well as file names. ... Recoll will index an MS-Word document stored as an attachment to an e-mail message

UltraSearch searches files on local NTFS drives. The freeware provides the results within just a few seconds.