I run Windows (for certain reasons, mind you) on one of my computers and during development, I realised the need for a diff utility on the Win platform. And point being, I don't have cygwin installed on that machine nor do I want to. So I ran accross this neat little utility called CSDiff, the shortened form of ComponentSoftware Diff for Windows. You can visit the website here.

Its a free utility so don't worry about getting a demo version or a limited period trial. Though I could start off by explaining every single feature it has (what the heck is the Help file for?), I'd rather stick to what I like best about the utility. Firstly and most importantly, the results are very nicely displayed. It just seems the natural and intuitive way to show them. Another big plus is that the utility is damn simple to use so newbies who haven't used the 'diff' command before would have no problems with it. Have a look if you're needing such a utility, it doesn't bite!