Getting Windows 7 admin account password?

I don't want to reset the password nor delete it. I need to know the password. What can be done? Specific software for that? Easier way of getting the password from inside a non-admin account through Windows itself or reboot is needed? Thanks

EDIT: Also, where are the password files stored? If I get in the system files with another bootable OS, I can read those and get the pwd from it.

EDIT: I don't want to reinstall Windows, I want the password.