Semestry says Not Found

The requested URL was not found on this server.

You have to make your customized 404 page larger than 512 bytes, otherwise IE will assume it's a standard web server 404 message and replace it with its ownfriendly-ized version. You have to make your customized 404 page larger than 512 bytes, otherwise IE will assume it's a standard web server 404 message and replace it with its ownfriendly-ized version.