GrepWin Portable is a simple search and replace tool which can use regular expressions to do its job. This allows to do much more powerful searches and replaces. In case you're not familiar with regular expressions, we have a very short regular expression tutorial for you. For example, you can (and maybe you should) limit the search to certain file sizes, file types, etc. Since regular expressions can sometimes get complicated, GrepWin Portable allows you to add your most used expressions to a presets list.