LOG IN!!!!!!!

Our company is a Server/Client environment. I have a software from a payroll agency. I installed it in a XP machine. Everytime you run the program under “Administrator” it gives a log in name and then you click on the name and type in the password and you get connected. But for some reason if i run the program with my user name it will not give me a login name to choose from. I would like to know if anybody in here nows WHY! and how I can fix this