I tried a couple of those Cd's that say they can change your windows password but they did not work on Windows 7 so I would not bother trying them.
The easiest way I found was to use a Ubuntu CD (Linux) any version should do just don't install it you just need to run it from the CD
with the demo version of Ubuntu loaded go to places look for your hard drive with windows on it then you have to change a couple of files
go to the Windows System 32 directory
rename utilman.exe to utilman.old, copy cmd.com to utilman.exe ( you are basically saving cmd.com to another name don't delete cmd.com)and reboot into windows
At the Windows log in prompt hit the “Windows”+”U” key and open pops a system level command prompt. From here you can type any windows command, add users,etc.
When your done rename all the files you changed back to what the were other wise you will be leaving a back door to your computer even though you are the only person that will know this
at the command prompt type
C:/>Net user John 123 /add
This command will add a new user named as John having password 123.
C:/>Net localgroup administrators john /add
This command will add limited user john to administrators group
from there reboot Windows log on as john with the password then change your old password
Click on the User Accounts and Family Safety link.
Note: If you're viewing the Large icons or Small icons view of Control Panel you won't see this link. Simply click on the User Accounts icon
Click on the User Accounts link.
Find the name of the account you want to change then change the password to whatever you want
After you are done change the files back to what they were