The bulletin below suggests that NetBEUI may not be included in the valuedeleted version of XP that is licensed to OEMs but that it is in a "valueadded" directory in the "full, retail-released version of Windows XP." May as well check your XP disk. There are two files you need, Netnbf.inf and Nbf.sys. If you can manage to get them, then details for manual installation are in the bulletin.
<a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q301041" target="_blank">http://support.microsoft.com/default.aspx?scid=kb;en-us;Q301041</a>