Okay, Noel, I think I may have found it. Whilst looking at Disk Manager and showing my younger brother how I couldn't get an initialize screen, I noticed the legend at the bottom that says "Unallocated" is in black and "Primary partition" is in blue, as in this screen shot:
When I right-clicked on the black bar on drive 1, the bar indicating that the entire disk was unallocated, the system responded with a "New Simple Volume Wizard" that looks like this:
Since what I wanted was a volume on a single disk, I clicked "Next", and saw this:
So I opted for the maximum disk space and clicked "Next", and saw this next screen:
After assigning the disk letter "E" (I would have preferred it be D, but the system assigned that letter to the DVD-ROM drive), I clicked "Next", and saw this:
After which, when I clicked Finish, the Wizard finished and activated the disk. It looks like you were right, Noel, that the disk was already initialized, and only needed to be formatted -- I did exactly what you were probably at the time writing that I should do. Thanks for your help.