Hello stoleaway and welcome to Seven Forums.
If you format a drive data will be erased. I'd hold off doing that.
Couple of things you can try. But before doing anything I'd suggest making at least a restore point or better yet, a system image, just in case.
- Since the external hard drive was detected earlier, I would suggest you try restoring your computer to an earlier date/time prior to when the problem first appeared. System Restore
- This Microsoft Fixit may help. Hardware devices are not working or are not detected in Windows
- You could also check in device manager if the external hard drive is listed there.
a. Connect the external hard drive to the computer.
b. To open device manager, type devmgmt.msc
in start search box and hit Enter.
c. Check if the external hard drive is listed.
d. In device manager, expand the hard drive listed in the device list.
e. If the hard drive is listed, right click on it > click Properties
f. In General
, under device status check for the message. Post back if there is any error message.
- Check if the external hard drive is getting detected in Disk Management. If it is and if there is no drive letter assigned, try assigning a drive letter and see if it helps. Drive Letter - Add, Change, or Remove in Windows 7
_ Remove and reinstall all USB controllers.
a. Open device manager as above.
b. Expand Universal Serial Bus controllers
c. Right-click every device under the Universal Serial Bus controllers
node, and then click Uninstall
to remove them one at a time.
d. Restart the computer, and then reinstall the USB controllers. Restarting the computer should install the drivers automatically.
e. Plug in the removable USB storage device, and see if the issue is resolved.
Please post back if any of this helped or not.