Microsoft Corp. has issued a security advisory to help force Windows users into applying a critical security update for Macromedia Inc.'s Flash Player, thereby dealing with a code bug that could be exploited by hackers to take complete control of a target machine.

The company urged all Windows users to upgrade to follow Macromedia's instructions for upgrading to the patched versions of the Flash Player.

The company also suggested a list of workarounds to help block known attack vectors, including instructions for temporarily preventing the Macromedia Flash Player ActiveX control from running in Internet Explorer.