Ok, if you are running XP and not XP-64 (you would know if you were, it's a very different product) then you are running 32 bit, not 64 bit. This is the operating system processing ability not the file system; that is most likely FAT-32.
That's good, that will make thing easier.
So, it works fine in OSX, no problem, but it isn't working in XP, and you basically have it setup direct USB connection and not wireless or some other print server. Good, that should make things easier.
Printer is on, and connected, should be if it is working in OSX.
First, I recommend this page :
http://welcome.solutions.brother.co...=hl2140_all&dlid=&flang=English&os=7&type2=-1
Download the driver uninstall app. Use that to remove the driver. Then download the driver only from that page and install that. You shouldn't need the full package.
Start -> Printers & Faxes
Click Add a Printer (top left of the window)
Click Next
Select "Local printer attached to this computer"
Check "Automatically detect and install my plug and play printer"
Click Next
It SHOULD find the printer and install the driver and you'd be good to go.
I am not at a place where I have one of those printers, I'll do it tonight if you're still having problems.
Good Luck. But if you need more immediate help, the Brother website has some good walkthrough's. When you are in Windows XP (bootcamp), you are basically on a windows machine 100%, so don't read anything about OSX just the Windows XP stuff.
I'll get more info for you tonight.