From DocFetcher Development Team:
DocFetcher Portable is an Open Source desktop search application. It allows you to search the contents of documents on your computer. You can think of it as Google for your local document repository. The program provides a preview panel with search term highlighting. The results can be sorted and filtered. The following document formats are supported: MS Office, OpenOffice.org, PDF, HTML, plain text, RTF, AbiWord, and CHM files. Features include Unicode support, archive support, search in source code files, Outlook PST files, detection of HTML pairs, Regex-based exclusion of files from indexing, Mime-type detection, and query syntax.