HELP!!!!!!!!!!!

I downloaded TweakUI 2 days ago. I must of made a change which requires me to enter my password in the Administrator screen in windows. I have Windows Media Center. I am using KNOPPIX for the first time. But I REALLY need to get access to my password or get around it somehow.

I have been up all night trying to figure out my password and can not seem to remember. This is not a stolen computer.

Also there is no restore CD. My computer came with VAIO recovery console. So I usually go there if I need to revover anything or start from scratch. I know I need to mae a disk next time.

But is there anything I can do? Is there a file I can get to through KNOPPIX that has my password?

Any help is apreciated.

Thanks!