The new PowerShell has a default irritating feature of keeping duplicate commands in the keyboard buffer. For example, if I had executed the command DIR ten times, pushing the Up Arrow will show ten DIR entries.
I tried to check the Discard Old Duplicates box in Properties/Options, but this did not work.
How do I turn off duplicate commands?
PowerShell in Windows 10 use PSReadline for better command line editing experience. PSReadline does not use normal console input buffer and so not affected by Discard Old Duplicates option. You should disable duplicates in PSReadline options:
Set-PSReadlineOption -HistoryNoDuplicates
You have to put that in your PowerShell profile, if you want this as default behavior.
