The only circumstances under which it won't work is Office 2010 64-bit on Windows 64-bit.

However, per David's answer below, I was mistaken about the circumstances in which my Declare statement won't work. I have a VBA application developed in Excel 2007, and it contains the following code to allow access to the ShellExecute function from Shell32.dll: Private Declare Function ShellExecute Lib 'shell32.dll' Alias 'ShellExecuteA' (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long