you could always just erase the password... you need a tool tho its called austrum. its a linux live cd that is bootable. you can download the ISO here. (use a burning program to burn the iso, and boot from the cd)
after you boot from the cd, it will ask how you want to boot the linux version.
enter: nt_pass as a boot option
it will then ask you to find the windows partition.
usally this its the default one, so go ahead press 1
next it should be prompting you for the location of the windows registery. (what it suggest in the brackets is usally right too) go head and try it... just hit enter
from here on out... its pretty straight foward 1 - password reset 1 - edit user data and password
it should then prompt for a user account to edit...
enter the one you wish to change the password for. * - enter * for blank password y - save our changes ! - quits the menu system q - quit the tool y - writes the data we saved in memory!
now you have a blank password, take the cd out... and restart. You now have no password on the account, just hit enter and your done.
This tool is pretty easy to use, ive used it a several times. if you follow the direction I gave ya, it should take you no longer than 5 min to be back into windows... if you need any assistance in doing it... post back here.