Does the enclosure support 1.5 TB?
Try partitioning it outside the enclosure with another computer.
The laptop may not support hard drives of that size without a bios update.
Have your prepared (that is, Partitioned and Formated) this new HDD for Windows' use? Or, did you buy a complete unit with these preparation steps already done? If they are not done, look through these forums for info on using Windows Disk Manager to do them, or check your drive's manufacturer's website for info and free software utilities to prepare and install a new drive.