External hard drive not visible

Hi all,
I have a 3TB external hard drive plugged in to my pc. I use it to stream movies and music to a couple of media players in the house via our wifi network. Recently it has disappeared from my view on the pc. When I plug it in via usb, nothing happens, yet when I plug it in to my daughters laptop it is recognised, leading me to believe it is a setting problem with my pc rather than a problem with the hard drive. Can anybody advise how to make it work again.
Many thanks,
Paul

Thanks for the replies, I have had a look in device manager, there was a usb device listed as CODE43, I assume this was my external hard drive. I googled code43 and followed the instructions to uninstall it and turn off the computer and unplug for 10 minutes, then start it but that hasn't cured it. When file explorer is open, down the left hand side where it lists the desktop, documents and the hard drives etc, under the network tab is listed my BT home hub and PAUL. If I click on Paul it lists the "G" drive which I cannot see elsewhere but when I double click it a window opens that says "\\PAUL\G (Samsung) is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. The device is not ready."
The hard drive is recognised if I plug it in to my daughters laptop. This hard drive has worked flawlessly for six months or so, I download music, films etc and transfer them onto it, it is shared from my pc and we have a media player in the living room and bedroom so we can stream said music, films etc to our tv.

Yeah, G was the letter for that hard drive when it worked. I have another external hard drive plugged in that works fine, I have plugged the G hard drive into the usb port that the other working hard drive is using but it still isn't recognised. I also think it's a permissions issue but can't work out how to solve it

I have no idea how to do that, I'm afraid