Follow the suggestions below and your pages will speed to your audience without a problem.
Web servers have rules what the first file in a web is a called.
Never use unusual characters within a file name. Name Extensions are fixed. That is, the file hello.htm is regarded as a different file than Hello.htm. If you use upper case, you need to be consistent in all your links to that file. These rules are simple, but novice web authors often forget them and end up scratching their heads when the result is a graphic that doesn't show up or a link that doesn't work.