Vim internal use of encoding (this settings is must if you like to use utf-8 or you would like to convert encoding from one to another). I strongly recommend to set this setting in _vimrc file (Windows equivalent of Linux .vimrc file). You can open your _vimrc file with command: :e $MYVIMRC
Bellow is actual setting that will convert to utf-8 when you execute :w (saving file). You can also set this in _vimrc file.
There is also smart to set encodings (notice "s" at the end of command).
Bellow settings tries to recognize the encoding of existing file when file is opened. I also suggest to save this setting in _vimrc file.
SAMPLE HOW TO CONVERT FILE ENCODING FROM ONE ENCODING TO ANOTHER
Now lets say you have a file in some other encoding like cp1250 (latin2) and you would like to convert encoding to utf-8.
Set internal Vim encoding to utf-8. A must have setting if multiple code pages are used and converting between them.
Open file and let Vim know what is your current encoding file is saved in (e.g. cp1250 for Eastern Europe encodings = latin2)
:e ++enc=cp1250 YourFile.txt
or if file already opened: :e! ++enc=cp1250
Set target file encoding to utf-8:
Now do actual save (conversion happens now):
set encoding) ?