Depending on your website a good way to work out is still active/usable is too run a link analyser from the homepage. (try Xenu)
That way you can get all the pages that can be navigated from your homepage and create a complete sitemap of your active site.
On a related note how do you find out what version of IIS you are running on NT4? Does anyone remember?
It has been so long since I used NT4 and I often used the option pack that has IIS4 on it but I sure I have used IIS3 and maybe 2 as well.