Look up NTPASSWD and you find this free software can reset that password.
In the future you'll want to have a spare second admin account so you don't have to fix it with NTPASSWD.
ok here we go.......i have a windows 2000 pro. nt pc. i've never created a username and password always just hit ok on adminsttrator with no password...now it is asking for a password, i've tried to log into safemodde reg. andd with command prompt. still asks for a password. wat can i do? helpp.......