I am trying to run the following code but get this error:

Compile Error: Sub or Function not defined.

Any ideas on how to fix this or why it is occurring would be greatly
appreciated.

Sub DeleteABC()
Dim FSO As Scripting.FileSystemObject
Dim FF As Scripting.Folder
Set FSO = New Scripting.FileSystemObject
Set FF = FSO.GetFolder("C:\Test") '<<< Change Folder

DoOneFolder FF, FSO
End Sub

Sub DoOneFolder(FF As Scripting.Folder, FSO As
Scripting.FileSystemObject)
Dim SubF As Scripting.Folder
Dim F As Scripting.File
For Each F In FF.Files
If StrComp(Left(F.Name, 3), "ABC", vbTextCompare) = 0 Then
Kill F.Path
End If
Next F
For Each SubF In FF.SubFolders
DoOneFolder SubF, FSO
Next SubF
End Sub