kingrobot

There is a website like iconverter that will convert icns to png and ico, I found it here: http://eisbox.net/iconvert/

If you just have a few png to convert to ico, this website will do it without installing any software: http://www.eisbox.net/iconvert/

You can do it online for free here: http://www.eisbox.net/iconvert/ It will go directly from .icns to .ico, .ico to .icns, and more as well. It doesn't support extracting windows 256x256 icons yet, but does 128x128 and just about everything else.