Sometimes I work with many files and I need to replace a phrase with another one in all the files or I need to see all the occurrences of a word in a file without the rest of the details. Windows Grep is a tool that makes your life easier if you need to correct an error in a lot of files. You can use regular expressions, recursive search in subfolders, filters for files.
Windows Grep can produce customizable output and automatically backups the original files.
While the interface may not seem very attractive, the program is powerful and is a good replacement for the Unix version of grep, a command line utility that reads a file and outputs the lines containing matches for a regular expression.
Although the program is shareware, it costs $29 and the author says "you are both legally and morally obliged to pay the license fee", the program works without limitations after the trial ends.