In the future, please start your own thread. It does not appear that your problem has much in common with that of the earlier poster, other than you both have an issue with an external drive.
Open Disk Management (Start > Run > diskmgmt.msc > OK)
Your portable drive should be shown there (probably as "Disk 1" in the bottom pane)
If the space on the drive shows as "Unallocated" (as in the figure above), right-click and select "New Partition." During the operation of the Wizard, you'll assign a drive letter. I suggest that your format using NTFS. After the drive has been partitioned, formatted and has a drive letter, it should show in My Computer.
If the drive is already partitioned and formatted, see if you can assign a drive letter by right-clicking on it.