External HD recognized, not appearing

Hi all,

I bought a new external hard drive the other day and connected it to my Toshiba laptop (Windows 7 Home Premium, 64-bit) and the laptop recognized the device and everything was working properly. I transferred some files to the external HD and then plugged it into another device to use the files and the files did not show up. I then connected the external HD back to my laptop and it was recognized (made the connection noise) and the device powered up, but it is not showing up in My Computer. I then checked in Device Manager and under 'Disk Drives' the external HD is listed with up to date drivers, though, in Disk Management, I don't see the device listed there.

Any thoughts as to what I can do to access the external HD on my laptop? I am currently running a scan on Testdisk 7 to ensure no files are damaged and such.

Thank you!