Greetings,
As Tong mentioned, NI does not make a PC/104 DAQ board, so I assuming you are using a third-party PC/104 DAQ board. If that third party company provides a compatible driver for Windows XP embedded, than you should be able to use LabVIEW to talk to the DLLs from this driver. I would contact your DAQ board vendor to be sure.
Also, take a look at the following thread:
http://forums.ni.com/ni/board/message?board.id=170&message.id=74555&requireLogin=False
Regards,
AnujD.