I Stumbled on this post many times, as I often need to handle huge files (10 Gigas+).
After being tired of buggy and pretty limited freeware, and not willing to pay fo costly editors after trial expired (not worth the money after all), I just used VIM for Windows with great success and satisfaction.
It is simply PERFECT for this need, fully customizable, with ALL feature one can think of when dealing with text files (searching, replacing, reading, etc. you name it)
I am very surprised nobody answered that (Except a previous answer but for MacOS)...
For the record I stumbled on it on this blog post, which wisely adviced it.