grepWin is a search and replace tool that can use regular expressions. This allows you to preform powerful search and replace functions with a simple intuitive user interface. grepWin adds context menu to the Windows Explorer shell easily search selected folders.Once started, grepWin allows you to customize the search or replace in many ways: File sizes, file types, Case Sensitive, Include/exclude system folders, etc...it also has a create backup function which can be VERY handy with bulk renaming. Since regular expressions can sometimes get complicated, grepWin allows you to add your most used expressions to a presets list.