The button on the FTW Transcriber’s interface called “open basic word processor” button opens Microsoft WordPad on your computer. You do not need to transcribe into WordPad – the FTW Transcriber can be used with any virtually word processor, including Word, Open Office, Google Drive, and countless others.
WordPad is a basic word processing program that comes as part of Windows. It is possible to uninstall it, but very few people do, so you probably have it on your computer.