I am looking for a program that searches all the files in a folder and changes the matching words. It would be better if it contained Regex.
You are looking for FAR - Find And Replace
Search and replace operations on file content across [sic] multiple files. Recursive operations within entire directory trees. FAR comes with support for regular expressions (regex) over multiple lines, automatic backup and various character encodings. Run grep like extractions to condense or rearrange sources, or perform bulk file renaming.
•Regular expressions over multiple lines •Simultaneous replacement operations on multiple files
•View matches, preview changes