
Press Save to create a new text file or copy and paste the text back into a text editor. The Remove Duplicate Lines option should already be selected in the drop down by default. Paste the text into the window and press the Do button. Go to the Tools menu > Scratchpad or press F2. Install (or extract the installer with 7-Zip to make it portable) and launch TextCrawler. Despite its power, TextCrawler is relatively easy to use and the remove duplicate lines option is actually found in a separate window, called the Scratchpad.

TextCrawler is a very powerful freeware program that is built mainly for the task of searching and replacing data in text files. A simple and common way to remove duplicate lines from a text file is to use a dedicated third party utility.
