search question from older example

regarding the example in this post
http://www.excelforum.com/excel-prog...file-path.html

what do I change to search the entire hard drive for files containing certain text? -meaning find all filenames containing text like the input cell on all of c:\ regardless of what folder or subfolder?

Here is the example from the other post if that makes things easier to answer. It works great, but I want to specify the whole c drive as the path and get it to look through all folders and subfolders.