If you’ve recently upgraded to Microsoft Vista, or purchased a PC with Vista pre-installed and want to use WinFax, you’re out of luck.  WinFax PRO will install under Microsoft Vista if you bypass the install warning message about compatibility, but it will not operate properly. The WinFax printer drivers will not install in Vista (it’s not compatible with the operating system due to Vista’s blocking of Kernel Mode printer drivers). The printer driver is the heart of WinFax, without it, you can’t send (“print”) faxes from your Windows applications, or can you attach documents. There are also several other incompatibilities that I have encountered, such as Fax Sharing (probably due to IPv6), and some application crashes/shutdowns when clicking on fields that happen to require number (digit) entry (usually these are within phonebooks, IP address, area codes, etc.). This is a known problem to occur after upgrading to Internet Explorer 7 or Service Pack 2 or 3 under Windows XP, this issue has been identified and resolved. I have not found any solution for this under Microsoft Vista.