Forgotten Macbook Air password

Hi there,

My partner has forgotten the password for their Macbook Air so can no longer install any new software.

We don't have a restore disc and have tried following the following instructions, from many sites and forums with no joy -

1. Boot into single user mode (press Command-S at power on)
2. Type fsck -fy
3. Type mount -uw /
4. Type launchctl load
/System/Library/LaunchDaemons/com.apple.DirectoryServices.plist
5. Type dscl . -passwd /Users/username password, replacing username with the
targeted user and password with the desired password.
6. Reboot
This allows you to reset the password in single user mode without booting
from the install media.

Is this something the Apple store could help with if I took the machine in, or are there any other resolves?

Thanks,

Tony.

If we were going to steal a laptop we'd aim for at least a Macbook Pro.

It didn't come with a CD or USB stick. We'll take our proof of purchase into the store.

Thanks.