You're going have to find a way to install the server on his laptop. If it is running Windows XP Pro you can try to log in with the administrator account. Sometime this account is not password protected. Heres how you do it, when the computer starts just before the windows logo keep pressing F8, then a list will show up, select safe mode with networking. Windows should display all account that is on that laptop. This only works for XP Pro.
XP Home you can't do, and I don't think you can do on Windows 2000 either. But there are programs out there that can reset the password, clear the password. You do not want to do this because he will know you were messing with his laptop if you clear out his password.
But there is a way to view his password, this is much too advanced and requires a bootable linux CD, you'll have to be able to copy the SAM and SECURITY hives from his system onto a floppy and use john the ripper to crack the password. I have the paper and documentation with step by step instruction from my instructor if you want to take a look. It's alot of work though.
BTW tell me what OS he is running on the laptop, I'll try to come up with some easy password cracker if I could.