I used Windows NT 3 to 4 and that's how you would log on back then. The CS\Cporter would be the domain name or possibly the local login. It's your machine so I expect you to recognize the machine's name and accounts.
http://support.microsoft.com/kb/308226 documents how to change the login.
I can't tell why it changed but the effect is well known and documented.
When we turn it on, it asks for CTRL,ALT,DELETE,
then asks us to log in as CS\Cporter.
Any idea what happened, or how to log in?
[Asus laptop running Windows 7.]