Changed the domian name to a workgroup and i can't log back in

I am a college student and I have a laptop that i rent from school. My school is on a domian. I am at a friend Lan party and I changed it from a domin name to a workgroup and now i can't log in at the start of windows is there anyway I can change it back to the domain name that it used to be.

thx

P.S I am running a dell latitude laptop with windows xp

Will booting to safe mode allow you to login and change it back?

that doesn't work b/c at the start of that it asks for the user name and password but still wont log on. Is there any way to change to domian name through dos or something?

at the login screen, press Ctrl+alt+del twice to bring up the standard login (if not there already) and click the options button, be sure that the "logon to" option has your computer name and not a domain. and its very likely that your username for the domain is not the same for the machine and/or because it is a rental you dont have persmissions to log on locally to the machine.(unlikely though, but possible)

You now cannot login as the domain user that you used to. You will have to login as a local admin. At the login screen, set the third box to (this computer). If you do not see a third box, click the Options button.

Hopefully you can remember the username and password of a local admin. Try username Administrator with no password.

Once logged in as a local admin, rejoin the computer to the school's domain. You should already know how to do this part since you've done it once before. You will need credentials that allow you to join the domain.

Anytime you change the PC's membership from a domain to a workgroup, you have to log in as a local admin to rejoin to the domain.