How to fix " class not registered !" message in Endnote 8.0.2 in connection with Word2007?

Dear firends,

I’ve installed the Endnote 8.0.2 in Word 2007 but whenever i wanna clik any tool in the Add-ins in Word 2007 i get the message" class not registered".i would be greatful if anybody tell me how to get over this bug.

Thanks in advance,

Reza P