tasklist.exe /s [computer name] /u [user name] /p [password]
At first try, I got an error message, "ERROR: Logon failure: unknown user name or bad password." I had to change network securtiy on XP machine:
Administrative Tools -> Local Security Settings -> Local Policies -> Security Options -> Network Access:Sharing and security model for local accounts". Set this to "Classic - local users and authenticate as themselves".