1)   Wanyword 4.00
Text search with Boolean and NEAR or proximity operators. ANSI/OEM search and conversion on the fly which is not unimportant since there is a lot of old DOS text around and umlauts and accents may give problems here. Sets of found files can be saved.
text search, boolean, near, cardfiler, editor,

 2)   Files Search Assistant 1.3.1
With Files Search Assistant you can search text in different file formats, for example in Acrobat Reader (PDF) documents, MS Office files (xls, doc). Preview pane and other options make your search efficient and rapid.
file, search, replace, PDF, doc, zip, preview, text search, search PDF, search in PDF,

 3)   Gobal Find & Replace 2.0
A powerful utility to automate the task of finding and replacing words or phases in text files. You can use this utility with folders and or individual text files.
advanced find and replace, text file search, text file replace, text replace, find text, text search,

 4)   AdScan32 1.3
AdScan32 is an advanced text search utility. Full text search can be combined with selective searches within user-defined data fields established around the regular structure of documents, if any. Extremely fast!
PDF search, RTF search, HTML search, DOC search, structured document search, structured text search, full text search, selective text search, text search,