Later The computer you are trying to use has too many connections and cannot assist you. The computer that houses the Web page cannot be located. The server could be busy, may be temporarily out of service, or may not exist. Check the URL to be sure it is correct. Your browser does not know how to display or execute a file.
Browsers use file extensions to determine how to execute a file.
If it sees .html, it will display the file as an .html file. If it sees .pdf, it tries to display it as an Adobe Acrobat file. This could be a clue that a plug-in is needed. Your browser is looking for a plug-in that will be able to execute the file. You may have it on your computer and just need to point your browser to it, or you may need to download additional software.