Maxtor External Harddrive.
It's used to transfer to video files from a mac and pc.
It's been used for at least a year, probably more (I've only been working with it for a year).

I plugged the usb into the pc and although it detects that a usb drive is connected and even says it's a maxtor drive, I can't view any of the files. I've opened up My Computer, and the drive isn't recognized. I've Run command e:\, gone to Disk Management and Computer Management but I can't see the drive there either. The only time I can view anything is when I go to Safely Remove Hardware.

The harddrive also makes a beeping noise when it's powered on.

Specifically, what are the beeps? How many? Long, short or both? Once you write that down, go to the manufacturer's web site support section. Those beeps may be indicating that there is a problem, similar to the POST test beeps.