How to open to in unknown encoding to edit (tw.pol) in Ubuntu?
When all else fails, use the terminal.
Try asking for some info on the file
Open it in vi (emacs if you must)
A quick google search tells me that .pol is a file extension used by Microsoft to manage registry keys.
If you cannot open a file with gedit, try the Gnome Hexadecimal Editor, which can be installed at the command line with:
sudo apt-get install ghex2
or search for hex editor in the ubuntu software center.