If you'd like to change the drive letter assigned to this drive, now is the best time to do that. See How To Change Drive Letters in Windows 7 for help.
Important: Assuming you chose to quick-format this hard drive, which I advised against in a previous step, please remember that the information on the hard drive isn't truly erased, it's just hidden from Windows and other operating systems. This is probably a perfectly acceptable situation if you're planning on using the drive again yourself after the format.
However, if you're formatting a hard drive because you're planning on removing it to sell, recycle, give away, etc., follow this tutorial again, choosing a full format, or see How To Wipe a Hard Drive for some other, arguably beter, methods of completely erasing a drive.