If you haven't already try to hook up your external hard drive to a different USB port on your computer.
In Windows, check if your drive shows in "Disk Management". To get to disk management, right click "My Computer" and choose "Manage". Disk management is on the left under "Storage". On bottom half of a screen you will see listings like Disk 0. An external drive would show as a disk other than 0. Generally, disk 1 or 2, but that can change depending on what else is installed on your system.If your drive is listed and has a drive letter assigned, minimize this window and check in "My Computer" for that letter. If it is there, that is your external drive. If a letter is not there or is assigned to another drive, like a network drive, you will need to manually set a drive letter.Bring disk management back up and right click on a capacity of your drive. Choose "Change Drive Letter and Path". Choose "Change" and select an available letter from a drop box.Once assigned a drive should be in "My Computer" with a letter you have selected. If that drive is listed as "Unknown" or "Unallocated" then that drive is not properly formatted for use with this computer. If your drive was used with a Mac or another non Windows device it may be using an incompatible format.This can be changed, but a process will erase all data on that drive. If a drive shows "Unknown", right click on a word "Unknown" and choose "Initialize". Click through accepting some defaults.Your drive should now be labeled "Unallocated". If that drive shows as "Unallocated", right click on a word "Unallocated" and choose "New Simple Volume". Keep clicking next, accepting default settings, until you get to finish. Clicking finish will begin a format process. A format will generally take 10 to 15 minutes, depending on drive size. When a format is complete your drive will be under "My Computer" labeled "New Volume". You can right click on that drive and choose rename if you would like a different label.
Unfortunately, the information you sent me didn't work, I could not follow your instructions. I could not find the the listing or the "Change Drive Letter and Path" button. I bought a new external drive.
Thank you anyway,