change administrator pass in win2k advan

HI
dear Sir.
I have change my administrator password in win 2k advance server with combine ” number + (alt+number)” for example “660? ” ,but at the next time i could not login againe .
Please help me how can login.
Best Regards
my adress : ali_rahimi@yahoo.com
a.rahimi@spc-ir.com
A. Rahimi