The windows password can be reset to a new one by anyone with the correct tools. Ask around your local shops. Explain what you need and one may be able to reset it for you. That would be your best bet as you then have full control of the system and a licensed install you can keep using. Make a new user for yourself if you want a different login.
Pulling the drive and putting it in a USB drive works. If you cannot get into specific directories you might have to take ownership of those directories. Google is your friend for that.
Pulling the battery seldom works on desktops anymore. It has not worked on laptops for many years.
Another way to approach the problem is to use a Linux load on a USB drive to boot the machine. That will let you browse the drive and copy files to the USB or to a backup drive. That might be the easiest if you are comfortable with making Linux USB thumb drives. I like Mint. ;-)
If the drive has had encryption enabled or there is a password loaded in the BIOS you have bigger problems. I'd pull the drive and see if the USB adapter worked.
FWIW I did a quick look. If it's 7 Home there is a free tool here:
http://www.lazesoft.com/lazesoft-rec...omparison.html
If you are comfortable with making what you need to you can try it. It was one of many. I have used tools like this in the past as part of my job. If you do not have some practice you can screw things up so I would pay somebody else who was in practice. YMMV. The other methods will give you access but not change anything so no damage done.