Ok well looks like this is too hard a question....

Anyway I did find a reference that indicates that Hardware handshaking is not supported by CDC.

In other matters....

CDC is not natively supported by windows Vista (no suprises there!). Windows XP just uses the default usbser.inf to install it, but that doesn't exist in Vista (yet?)

You can get the virtual comport to work in Vista by following this link -> http://www.obddiag.net/drivers.html

Also Vista no longer has Hyperterminal!

However you can download a (private use version) from here and it works for Vista -> http://www.hilgraeve.com/htpe/download.html

Cheers
Squib