then why the hell would you put a login and password in your program?? the fact that your pc is running doesn't necessarily means you are working on it. if it is an application that deals with sensitive data, you might want to reconsider a bit. I can understand the part where you want the user-name to be automatically set to the login in Windows, but dropping the prompt for a password, would be the same as: not giving the application to those who don't need it.

now, concerning your question, a couple of days ago, someone asked a similar question. you might get some help out of the response he got. it shows how you let your app automatically find the user that is logged in on Windows. Read me

What will this application be using for its source of authentication? Does it access network resources which require LDAP authentication?

the info stored in your System. I've never really used it, so haven't looked into it, but knock yourself out and go check for yourself.

if there is no answer to be found on http://java.sun.com, Google will propably be able to help you out

yes using LDAP i have to do it .

Do some google searching for JNDI and see if you can come up with any resources to help out. I'm familiar with the concepts, but have never implemented them. So at this point, google will be your friend.