Decoding Error Messages
As you surf the Net, you will undoubtedly discover that at times you can't access certain websites. Why, you might wonder? Error messages attempt to explain the reason for that and other problems. Unfortunately, these cryptic messages baffle most people. Don't worry: We've deciphered the most common ones:400 - Bad Request
Problem: There's something wrong with the address you entered. You may not be authorized to access the web page, or maybe it no longer exists.
Solution: Check the address carefully, especially if the address is long. Make sure that the slashes are correct (they should be forward slashes) and that all the names are properly spelled. Web addresses are case sensitive, so check that the names are capitalized in your entry as they are in the original reference to the website.401 - Unauthorized
Problem: You can't access a website because you're not on the guest list, your password is invalid or you have entered your password incorrectly.
Solution: If you think you have authorization, try typing your password again. Remember that passwords are case sensitive.403 - Forbidden
Problem: Essentially the same as a 401.
Solution: Try entering your password again or move on to another site.404 - Not Found
Problem: Either the web page no longer exists on the server or it is nowhere to be found.
Solution: Check the address carefully and try entering it again. You might also see if the site has a search box. If so, use it to hunt for the document. (It's not uncommon for pages to change their addresses when a website is redesigned.) To get to the home page of the site, delete everything after the domain name and hit the Enter or Return key.
For example, if the address is: http://www.learnthenet.com/english/html/96error.htm remove english/html/96error.htm.503 - Service unavailable
Problem: Your Internet service provider (ISP) or your Internet connection may be down.
Solution: Take a stretch, wait a few minutes and try again. If you still have no luck, phone your ISP or system administrator.