Firstly, you will more than likely have to re-install Windows. Windows tends to be very picky about changes to hard drive settings such as moving the drive to a new motherboard. More often than not, doing so will simply result in a blue screen crash (which, depending on how Windows is configured may simply cause an endless reboot cycle like you are seeing).
If you boot off the Windows XP CD you can go through the installation to the point of selecting which drive to install it on. If you just see the 120GB Maxtor and not the 1TB SATA drive, that's fine for now (in most cases, you'd need to provide the drivers on a floppy disk to have the installer detect a SATA drive). Since you are using an IDE drive as your boot disk, it's not really needed. You'll probably want to format the drive (make sure anything you may need is backed up) and do a clean installation.
I'm presuming that you are custom-building a computer. If so, once Windows finishes installing, you can either use the CD bundled with the motherboard to install things like the aforementioned SATA driver, or (better yet) visit the manufacturer's webpage and download the latest drivers for the board.
Hope this helps.