Check out Agent Ransack. It can do this among many other things:
Agent Ransack is a free tool for
finding files and information on your
hard drive fast and efficiently. When
searching the contents of files Agent
Ransack displays the text found so you
can quickly browse the results without
having to separately open each file!
Agent Ransack provides compelling
advantages over similar search tools:
- Regular expressions that allow complex rule based searches.
- Immediate contents results view.
- Various wizards to walk the user through the searching process.
Agent Ransack is provided FREE of
charge for the benefit of the Windows
community. If you find it useful
please register it, free of charge.
Windows Grep is another great tool that does the job: