Get "The page cannot be found" error when I know the link is good

I am running WinXP Pro with IIS 5.1 and I added an educational ebook off a cd to my website, but pages do not load and I get error that "The page cannot be found". I tried the path on the localhost and they work fine with Windows Explorer. The htm page comes up fine. The page is made up with frames and the left navigation frame works fine, but when clicking on the links that should open up in the main frame I get "The page cannot be found". When looking at the ebook on localhost, it works fine and all navigations work with no problem. I'm a bit confused as to how this could be.

Any help would be greatly appreciated!

The problem was that there were periods in the subfolder names. Once I removed them, it worked fine.