can?t sign on to Administrator…WinXP

Yesterday I tried to get on a PC at work. I am the Adminstrator, when Win XP starts the icon for my Admin user account was gone, I typed Administrator in the user spot and my password, the password won?t work, another friend tried it and he got on once. I find the user under admin tools. But I cant log on, and the icon is gone. the big problem is all the main programs that are used for work are in that account.