Compare user input to computer password?

[R23MJ]

Hello again,
I was planning on making a program, which requires login, catch is, instead of the user choosing there password on first launch, it uses the computers password. Now, I am not sure, but I think I read somewhere that Windows never actually keeps a record of what the password is, just a hashed form and compares on login. This is exactly what I want to do. Can anyone help me with this task?

Edit::
Not required, but something that would help is detection if there is no password set.

[giblit]

Windows pre-xp store the password in plain text but after that it is hashed. I can't think of anything to validate that except maybe one of these functions http://msdn.microsoft.com/en-us/library/windows/desktop/aa378184(v=vs.85).aspx The alternative would probably be to grab the password before they logon maybe though could be a security risk.