USAFRet :
If you tell us what you are trying to accomplish, maybe we can come up with a solution.
What is the reasoning behind "the exact same drive letter"?
Ok let me give you a little more background. For cloning and replacing my main backup drive it isn't totally important that it takes the same drive letter. However, I am using Crashplan and if it takes on the same drive letter, it will make everything a little more seamless.
Now, I have 4 drives that are all filling up. Replacing this first drive is sort of a test run. Replacing my other 3 drives will be much more important for taking on the exact same drive letter as the ones they are replacing. I have Mari, Maya, Premiere, AE, and various other programs setup for animation, texture, simulation, and video cache files for specific drives in addition to other various files. So taking on the same drive letter will make for a more seamless process.
In addition, my C drive is an SSD. I have my documents folder, desktop, music, pictures, etc. all on my G drive. So when I replace that drive, being able to take on the same drive letter will save setting all that up again.
So I am using this first replacement drive, the backup, as a way to test that this will work properly.
popatim :
Assuming you are talking about the main backup drive, you can clone it to the 4tb and then use disk management to expand the partition and change the drive letter to what you want.
Can't you only change drive letters to a letter that is not already in use? I need to be able to have a drive "adopt" a letter that is already in use.