If the password is the password to Windows, and if it is the administrator password, the only way to get past it within Windows is to reinstall the operating system.
No. No, and No again!
It is incredibly easy to hack the SAM database on a Windows box, up to Windows 7, and erase the administrator (or other account) password. Can also be done on Windows servers - not domain controllers - provided you have the right storage array drivers for the system disk.
Petter Nordahl-Hagen has a great tool (bootable Linux CD) for this, and there are many other password cracking / blanking tools.
Here's a few:
Offline NT Password & Registry Editor Review - Password Recovery Software Review - Password Crack ISO Download
SD