Well, I think I have now completed the i2 Match Type Catalog Installer.
MSXML 4.0 is out of the window and in comes wininet.
As Wininet was introduced with IE3.0 it safe to assume all computers will have this API set as part of Windows. It works really well and has two http download methods as well as ftp functionality.
Job done.

Found out MSXML 4.0 gives a...
Reference to undeclared namespace prefix : 'lcx'
when loading the LibraryCatalogue xml so have spent the last two days trying to solve it... nearly done now.