Should be possible. I've done the same a few years ago. Can't remember exactly what I did but think I started the pc in Safe Mode then managed to run the recovery software built in to restore it to factory condition
The best approach is to download the OS install ISO from Microsoft and make a disc using another (a friend's perhaps?) PC. Then you can boot directly from that to reinstall the OS from scratch. Even if you do get in you'll want to do that because who knows what might be installed. You'll never be able to trust the security of your data if you don't clean install.
What is password protected ?
Does the computer even start ?
How long does it load, where does it stop ?
BIOS (settings, start, hard drive password), windows account, windows partitions ?