THE ALL-EMBRACING tentacles of Microsoft are entwining around the domestic TV set with its announcement of a new set-top device that allows viewers to access the Internet via ordinary TV transmissions. Developed by Microsoft subsidiary WebTV, the device contains a video modem that converts special TV signals into viewable Web pages. The data will be transmitted at night and stored on a 1.1 gigabyte hard disk within the ‘box': this will hold up to twelve hours of VHS-quality video or thousands of pre-selected pages from favourite Web sites. Users still have to connect to the Net via a standard modem for outward activity - or for interactivity with television programmes - but downloading of data take splace via a simple TV aerial. The new system will be in US shops in time for Christmas and will also be marketed heavily in Europe. As of next year Its special appeal to the European market will be the avoidance of telephone charges whilst downloading from the Web. In the US the ‘box' will retail for $299 or a monthly subscription of $19.95.