Code:
'' Use notepad to save as "FixFileNames.vbs"
'' Update sFolder variable (remember trailing backslash)
'' Run by double clicking or on command line with:
'' cscript FixFileNames.vbs
Const sFolder = "C:\SomeFiles\"
Set fso = CreateObject("Scripting.FileSystemObject")
For Each file In fso.GetFolder(sFolder).Files
sNewFileName = Replace(file.Name, "_", " ")
sNewFileName = LCase(sNewFileName)
If (sNewFileName <> file.Name) Then
WScript.Echo "Changing '" & file.Name & "' to '" & _
sNewFileName & "'..." & vbCrLf
file.Move sFolder & sNewFileName
End If
Next