When it comes to searching for files on your computer, there are several options. But if you need to search inside documents, then you need a very specific tool such as DocFetcher.
With DocFetcher you can scan through documents stored on your computer and find words and sentences inside the text – not just in the file's name. The program creates an index with selected folders and then lets you look through the contents of those folders, without having to open and search every single file individually.
Before using DocFetcher, you'll need to pick the folder you want the program to index, by right clicking the Search Scope field on the left side of the interface. This indexing is not automatic, but can be easily updated by pressing F5. Plus you can use filters such as maximum size or file type to obtain better results.
DocFetcher supports all popular formats (DOC, HTML, TXT, PDF, PPT, XLS and many more) but unfortunately it didn't seem to work with PDFs during our tests. The program has a built-in viewer to preview search results.
With DocFetcher you can search inside documents in a variety of formats.