Startup Idea: Universal Document Search Tool

Startup idea to create a software program that can search for text across all types of document files, including databases, html files, excel files, and more obscure file types, specifically aimed at those in the lawyer consultancy business but can be useful for anyone dealing with diverse file types.

I would like a program that could search for all texts across ALL types of documents such as databases, html files, excel files, and even the more obscure files. I work in the lawyer consultancy business. I have many clients with information in all file types. It would be useful to have one program that can search through all types of files on my computer. I would pay a decent amount for it. I currently use something called DocFetcher. But it does not account for all file types.