By now, many Sage ERP users know that Sage 100 is only compatible with Windows 10 on versions 2016 and 2015, Product Update 4. Unfortunately, some of those users have learned the hard way about the incompatibility issues presented by running earlier versions of Sage 100, or MAS90, with Microsoft's latest operating system. To complicate matters, Microsoft has now released a program through Windows Automatic Updates that magically installs Windows 10 on workstations. The GWX.exe (i.e. "Get Windows 10") program is that unwelcome magician for users of earlier Sage ERP versions.