can't log on to pc

[Maggie Martin]

I accidentally changed a setting on my pc now I can't log on except through Windows, but I don't have an account or if I do I can't remember.all I get is a black screen and a message saying sign in by windows.I have no other options not even my control panel.can someone please help
Thanks

 

[jesseg123]

Are you sure the version of Windows you have is XP?