I have a Western Digital Drive that can be seen as a USB device (external HDD) but the computer will not access it or assign a drive letter I can load and eject it but thats all - are there any programs out there that will solve this problem.
Please tell us as much as possible about your computer system, Manufacturer, OS, and what HDD's you have attached to it. Also if anything significant was going on when you began having trouble with your ext USB HDD. Also have you been using the USB HDD on any other computers, assigning it a prior drive letter?
Running Windows 7?, go to Disk Management, and, in the lower graphical area, list what is being seen by Windows. You should have on the left part, Disk 0 as your system drive, then Disk 1 or Disk 2 which recognizes this USB drive. In the right graphical section, there should be the Drive Name, Disk letter assignment, Disk Size, NTFS, and listed as Healthy. There should be a Blue band above it indicating a Pri Partition.
Right click on the graphic, and choose "change Drive Letter and Path" and if assigned a drive letter, assign it an unused drive letter, like "K" for backUp.
Then see if the drive is recognized giving to access to it's contents.