external Hard Drives doesn't show in 'My computer'

I recently noticed an issue when trying to connect to external hard drives. Initially noted that it wasn't showing in 'my computer' and so assumed I had driver issues and sought to update them from Dell's site. After doing so there was still no change, but noted that It was appearing in 'device manager'.

I even tried updating the USB hubs from the Device Manager, and it states that they are all up-to-date with the correct drivers.

Both external hard drives that i have tried has worked on other PC's so i assume that mine is the issue.

~Dell 1525, Windows 7 Home Premium 64bit~

I have had a similar problem recently, where the hdd would spin up but not show in my computer.
After googling it I found that if I shut down the computer, completely not hibernate or anything, and leave it for about 30 minutes an then switch it on again.

In left mine overnight, 8 hours or so and it worked after that. My hdd worked in all the other ports, but not that one until I left it overnight.

Good luck with it.

Tom