I'm trying to work out how to convert a file to UTF-8, but I really can't find much useful info on google other than to use iconv. I downloaded that, but when I ran it via the CLI it told me that I hadn't installed it properly. The file I'm trying to handle is a rather large file (5M lines).
Notepad++ provides an easy (manual) way to do it. Open your file, choose "Encoding > Convert to UTF-8", and save. I think the size limit is 2 GB.
One option is to download Cygwin. Cygwin lets you use the Linux command line from within Windows. One advantage of using Cygwin is you don't have to worry about adding a program to the PATH as you would if you used the Windows command line. So download Cygwin and be sure to search for and select the iconv tool in your download. Then you can follow the example at this StackOverflow question. For instance it says,
iconv -f UTF-8 -t ISO-8859-15 in.txt > out.txt
where UTF-8 is the starting encoding of in.txt and ISO-8859-15 is the output you'd like out.txt to be.