Help!... External Hard drive problems

Hello everyone.

I switched to the mac about 3 weeks ago, I love it. But I've started to have problems with my external HDD. When I plugged the drive in, OSX didn't see it at all. Disk Utility saw it so I tried to unmount it, Disk Utility said that a program was trying to use the drive so it couldn't eject it. I had nothing running. So I shutdown the computer, when i turned it back on the drive was sitting there on my desktop like nothing was wrong.

Then the computer went to sleep, I woke it up and the drive is gone. I loaded up Disk Utility and it didn't show the drive. I reset the computer, and nothing. Now I can't get the drive to show up anymore.

Please help.

What is the format of the drive and how is it connected?

The Drive is formatted HFS+ Journaled. It's connected by USB, it's a bus powered drive that's worked until today.

Look under Finder>Preferences to the General tab and make sure that "Hard Disks" are selected to display on the desktop.

Have you tried any different ports? Powered down and restarted the external?

Could also try looking in Terminal.
Open Terminal (applications/utilities)

Type in the command cd /Volumes and enter.

Now type ls -la and enter.

This command lists the names of the drives mounted on your system. One of the names will be your boot drive. The other drive listed should be the name of your external drive.

If there is only your boot drive listed, then you may have bigger problems with the drive. You may need something like DiskWarrior.