If you can get into the normally hidden default Admin account, then you can change the passwords of all other accounts from there. The password is what was entered when Windows was first installed (if any). At the Welcome Login Screen hit Ctrl>Alt>Del twice and you'll get a Windows 2000-style login box. Type "Administrator" for the username and whatever password was entered when Windows was first installed (if any). To get to the default Admin account in Home Edition you need to boot into Safe Mode first.

Other than that we cannot help, for the reasons stated.