External Drive showing only in system profiler
If disk utility does not even see it the electronics in the drive may have failed. System Profiler may show a drive there but if disk utility cant access it, well... "Houston we have a problem."

If it IS an external you could try unplugging any other USB devices and/or trying another USB port and possibly even a different USB cable. If you can easily open the case without voiding the warranty you could check cabling there as well. But that might be a waste of time. Drive enclosures are pretty reliable these days. 

Failing that you might try a 3rd party disk utility. But I am not sanguine about the prospects. If Disk Utility doesn't even see the drive there is a good possibility nothing else will. It may be time for a new drive.