Mac files-->PC. Need file extensions!

Factual Questions
1

Background: My wife used to own a mac running Mac OS 10.3. Its old and slow, and she needed a new Windows XP laptop for grad school so we bought one. However, when I transfered the files from her mac to the laptop I realized that the files were missing file extensions (they never had them to begin with). Currently the data files are on both her mac and her laptop.

Problem: Hundreds of data files of multiple formats in dozens of folders need the proper extensions so they can be easily opened.

Question: I assume the Mac knows what kind of file each one is… so I was wondering if there is some way for the mac to put all of the file extensions on all of the files. Can the OS do this? Is there a program to do this? Help me!

(PS. No, the file extensions are not just hidden, they are non existent.)

2

If you are able to first group your files by filetype, something like a batch renaming program could help you out.

Here’s an example of one.

Using this or something like it, put all your Word documents (for example) into one folder and then run the batch rename to add the file extensions to each file.