# assign a letter to a Drive partition
# Type the steps one by one in command prompt
# You shouldn't type the lines that begin with #
--------------
# oepn diskpart
diskpart
--------------
# list the partitions on the selected disk
list volume
--------------
# now select the partition you want to assign a letter to(in this case we'll select partition 0)
select volume 0
--------------
# and finally assign the letter you want to selected partition(in this case we'll assign letter D)
assign letter=D
--------------
# Done, now exit.
exit
--------------