My external hard drive suddenly appears empty. it contained backups of my dvd co

did you recently drop the hdd?

I would try taking out the drive and attaching it internally into your computer, if you are still unable to read the drive, it might have gone bad.

Also, try running a CHKDSK on that drive to see if there are any bad sectors.

The hard drive wasn't dropped. It's a sata and was plugged into a Blacx docking station. It was fine one moment and not the next. Whatever happened was instant. I previously said there was 50 movies backed up on it. Actually there was 140 movies. It's a sata 750 GB Seagate Barracuda HD. It hasn't been treated rough at all. It wasn't moved from it's position prior to this problem. It isn't bad. It's like something is telling the PC there's nothing on it. No one else uses this PC. I have other PCs and they read it the same way. I feel the data is still there but I'm at a loss to recover it. It's a good thing I have all of these movies on DVD. It appears home computer technology is unreliable. I am a PC tech and this one stumps me. Any response is welcome from anyone who may have suggestions.

Likely that you (in)advertently improperly dismounted the dive.

I've had that happen (yes, I have the fat finger disease), and found that using Disk Management to merely assign a drive letter fixes things. Maybe this will work for you?