As microsoft betatester, I downloaded the iso file of Windows 8.0 build 8102 (32 bit / 2,8 GB iso file) and installed it. After the installation of MS Office 2007Pro plus and EndNote X5 (fullversion), the CWYW extension was correctly inserted in Word 2007 and works properly.
Windows 8.0 was installed last week and updated itself. EN X5 started problemless without or with Word 2007.
Another results in due course.
The joined screenshot shows EN X5 and the CWYW extension (red arrows)