Using Windows/DOS shell/batch commands, how do I take a file and only keep unique lines?

Question

Say I have a file like:

apple
pear
lemon
lemon
pear
orange
lemon

How do I make it so that I only keep the unique lines, so I get:

Answer 1

I also used Powershell from the command prompt, in the directory in which my text file is located, and then I used the cat command, the sort command, and Get-Unique cmdlet, as mentioned at http://blogs.technet.com/b/heyscriptingguy/archive/2012/01/15/use-powershell-to-choose-unique-objects-from-a-sorted-list.aspx.

It looked like this:

PS C:\Users\username\Documents\VDI> cat .\cde-smb-incxxxxxxxx.txt | sort | Get-Unique > .\cde-smb-incxxxxxxx-sorted.txt