TL:DR; Search files with smart queries as with Google, replace simple or multiline text in multiple files.
Download Advanced Find and Replace Shareware - Rating: 4.12
Instant File Name Search is a freeware tool for instant searches. Find files by name, part of name or wildcards (*.doc, photo??.jpg, *shrek*.avi etc.) on your PC or LAN. It is easy to use and useful software for Windows.
Document Finder enables you to easily and quickly find the information you want through all files on your hard disk by performing speedy full-text search. Supported file types include PDF, DOC, RTF, TXT, PPT, XLS, HTM, ZIP, RAR, CAB, LZH, TAR etc.
Search and replace multiple occurrences of text in many files. Load the files you want to search into the program and provide the text to find and the text to replace. The replacing is done quickly as a batch.