Попробуйте эту функцию:
Sub DeleteZeroLengthFile(ByRef sFilePath As String)
' Inputs: sFilePath Filename or path name of file to be tested.
' Outputs: <None>
' In/Outs: <None>
' Errors: Will raise error if file doesn't exist, is inaccessible, is locked, or user
' doesn't have permissions.
If FileLen(sFilePath) = 0 Then
Kill sFilePath
End If
End Sub