I bought a web server form 1and1 and when there is a 404 error it goes to one of their error pages. They say I can make my own. How do I do this, do do this through them, or can I just uplaod one through my ftp access.
You can create one just like you would any html page, and upload it into your root, name it something like error_404.htm or you could even make an error_pages directory and just name it 404.htm (whatever you like) then, create a .htaccess file (just create it in notepad and save with the file name .htaccess) that contains the following rewrite rule
ErrorDocument [errorcode] [page location]
ErrorDocument 404 error_pages/404.html