Alright, I have personally used this program: http://www.petri.co.il/forgot_administrator_password.htm
Its a free download utility, that you burn to a cd, and then put it in upon starting the computer and it will allow you to regain access to wipe the password and start fresh.
If for any reason that doesn't work, you can do the following:
Please try this: http://loginrecovery.com/
If you still cannot get into your computer, I would advise to reinstall Windows Vista(if you don't have the reinstall or window's vista discs you can contact the manufacturer of your computer for them), you do get the option during the install to save your current files, sometimes it doesn't work 100% though. So if you have files on your computer that are not not easy to get back(irreplaceable), I would advise to take the hard drive out, take it to a Data Recovery Center(most local computer shops can also, get your data off the hard drive) Then get a new hard drive and install windows.
Glad I could be of assistance, If you need anymore help please ask, otherwise have a good night and god bless!
Please accept so I can be compensated for my time/work, also feedback is highly appreciated!