Hello KEMLTD,
Your installer is correct, Adagio is not compatible with XP/Winfax - but it is compatible with XP, and does not require any faxing software as all the necessary components are supplied with Adagio. All you need is a fax modem on one of the computers running Adagio and a connection to the phone system.
In the module you are trying to fax from, select File | Options and make sure that faxing is enabled for the station. You should then see a fax button available where you can print statements or invoices. The document will be generated and the telephone number automatically retrieved for the customer. Adagio supports full 10-digit dialing with long distance rules and dialing prefixes and suffixes.
Winfax requires you to "print" to their fax driver and then provide a fax number to send it to. This procss should still work, assuming you can get Winfax to run under XP. However, the Adagio fax automatically finds the correct number from the customer file.
As this question is more of a technical support inquiry, I'll move your post to that forum.