I've found that Windows FAX, on whatever version of Windows, is more trouble than it's worth.
Unless, or until, FAX is enabled to operate directly on a broadband line (unlikely as it's such an old technology) you are going to need a dial-up modem on your computer. These are becoming quite rare now.
The alternative is a dedicated FAX machine or use a FAX service company which is fiddly and involved and not really worth the trouble.
You can get multifunction printers with a FAX facility at a quite reasonable cost. You can use these either through your computer or independently (thus more convenient). In addition, you don't have the potential problem of having a dial-up modem attached to the computer with the danger of unknowingly downloading things you would rather not have into your machine.