"Just use NTPASSWD, it's been around forever. A lot of Linux bootable recovery systems have it built in.
http://pogostick.net/~pnh/ntpasswd/
Update (09/08/2017)
It has been a while since my original comment.
I've used (and still use) ntpasswd for many years from XP thru Windows 8 on hundreds of systems and have blanked out the user admin password. The key word here is BLANK out the password.
It is just a matter of following the menus by selecting the drive with the sam file, listing the windows accounts, unlocking the account using the id of the account, it will be something like 0x01b3, then selecting the option to blank the password. Last, when you quit, it will ask if you would like to write the changes. Restart and at the Windows login screen click on the account that was unlocked and leave the password field blank. Once inside Windows you can go to the user account and set a new password.
For Windows 10 systems, with a Local Account (only), I've used this guide several times without a problem.
First of all I would try the simplest route. There is an Administrator account that is created with every windows Xp install. At the login screen, hit alt+ctrl+del 2 times, it should give you another login box, it may have a user name already inside it. Delete the user name, and type, ""Administrator"" no quotes. Hit enter, and it should log you in with admin privileges. From there goto Control Panel > User Accounts and change the passwords to your liking.
Second you can use the F8 key during windows startup. Continually hit F8 when your computer first turns on, BEFORE the windows screen loads. It will prompt you with choices on how to boot windows. Choose Safe Mode, and goto Control Panel > User Accounts and change the passwords there.
"For those who are locked out of their computer and want their data, and in case a password removal disk did not work, here's a fix I use all the time:
- Power down laptop, disconnect from charger, remove or disconnect battery;
- Remove HDD;
- Put it in a USB enclosure; connect it to a Mac or Linux based system; if it's a Mac, make sure it has something like ""Paragon NTFS"" installed in order for it to read NTFS drives;
- Access the ""user"" files as if it was an external storage, and copy the needed data;
- Put back the hard disk in your computer, reconnect battery;
- Format or reset to factory settings depending on what configuration you have, such as access from a different admin user. Re-install OS, softwares, and copy data back.
