MJREM,
For Windows, most Hard drives should be formatted as NTFS
Also, how did you format the Hard Drive? With another computer?
Even if a Hard drive is not formatted correctly, the system will see it when you plug it into the USB port. However, the system might not assign it a drive letter.
To see if your drive is present, but not mounted, go into tghe administrative tools and find the disk manager. The disk manager lists all drives, including any that do not have drive letters.
you get to the administrative things in control panel.