如何删除文本上的重复项

I want a tool or how to use notepad++ or any other tools to delete both duplicates lines in a text, all tools I found delete only the duplicate line and leaves the original

I want to delete them both , like that:

line1
line2
line2
line3

i want the result be :

line1
line3

How about:

Find what: ^(.+)\R([\s\S]+)\R\1
Replace with: Nothing

Make sure you've selected Regular expression and NOT Dot matches newline
Click on Replace all as many times as necessary.

Edit:
Depending on your version of npp, you could use instead:

Find what: ^(.+)[ ]+([\s\S]+)[ ]+\1
Replace with: Nothing