How to Find Duplicate Files with PowerShell

cd <DirectoryForRecursiveSearch>

gci * -Recurse | get-filehash -Algorithm MD5 | Group-Object hash | ?{$_.count -gt 1}  | select @{n='DupeCount';e={$_.Count}}, @{n='DupeFiles';e={$_.Group.Path -join [System.Environment]::NewLine}} | Out-GridView

Get-ChildItem -Recurse | Get-FileHash | Group-Object -Property Hash | Where-Object Count -GT 1 | foreach {$_.Group | select Path, Hash}