There are many password recovery tools that you can use to either recover or change your password to allow to access your account again. Some of these are free, some cost money for the program and some cost money for dependencies.
The first program I am going to cover will be the NT Password and Registry Editor. This tool will not recover your passwords, instead it allows you to delete your current password to regain access to your account. This a free tool and can be downloaded from here. Also there is a step-by-step guide here.
The second application is OphCrack, which is a boot-able CD/USB that cracks your password. This tool is free and comes with a few rainbow tables for each operating system. Rainbow tables are pre-hashed passwords that expedite the cracking process by time-memory trade-off. If your password is complex you might need to create or purchase additional tables to crack your password.
The last application is Kon-Boot, which is yet another boot-able CD/USB that bypasses the need for a password. There is a free version of this tool that you can bypass some logins for most 32-bit Windows systems. There is a full version that only cost $15 and bypasses any Windows Machine not connected to a domain. Once you gain access you can change the password to maintain access to your account.