How to filter repeated lines from a text file on windows?

Download and use uniq.exe utility.
It displays unique lines of a sorted file.Got to use -d switch.

-d
displays only lines which are repeated (one copy of each line).

-u
displays only those lines which are not repeated.


Example
uniq -d input_file output_file

Download from here
https://www.securinfos.info/OPCODES_LIST.RAR