Cannot Change User Password In System Recovery

I'm working on a Windows 7 laptop for which the user has forgotten the password. So, putting my windows 7 DVD in, I boot into System Recovery and go to a command window. I try to change the user password for "User X" as it displays at login, and the system kindly informs me "User X" doesn't exist.

Using net user, I see that the only two users that exist are "Administrator" and "Guest". So, I activate administrator using "net user administrator /activate:yes". Then I change the password of administrator.

Rebooting into safe mode, I find "User X" and "Guest" still my only options. I try the password I set for administrator (since User X doesn't exist), but that doesn't work.