Windows Powershell
How to start powershell
Go to the start menu and type powershell in the search and then click on it.
To rename all the files in the Desktop replacing space with _
Dir | Rename-Item –NewName { $_.name –replace “ “,”_” }
To keep the first 5 charaters and drop the next 2 use:
Dir | Rename-Item -NewName { $_.name.Remove(5,2) }