HARD DRIVE NOT RESPONDING

Hello,

I have been using my new hard drive fine (for about 3 months) until i tried to change the name of it to "JOE HARD DRIVE". Ever since my PC nor laptop will allow me to open my hard drive. I thought it was because it neded another drive letter to read so i changed the drive letter to (z:) by this process:-

Right click on my computer
Choose MANAGE
Then find DISK MANAGEMENT
Right click on ext hard drive under the list.,
and choose CHANGE DRIVE LETTER


Still no luck. Both Laptop and PC recognise a new drive but when i go to my computer, the hard drive is known as Removable Disk (z:) and it wont allow me to open it. A message comes up saying

"please insert a disk into Removable Disk (z:)"


Anyone ever experienced this before and knows what to do ????