Hi Wendy I'm not sure that I quite understand what I am going to paste below but it seems to explain, up to a point, what you want to know. I found it in a web page ages ago. Carlos. >> DEVICE CHAINING MANAGER (DCM) NEEDED FOR WINDOWS XP >> In many instances, such as instructional facilities, and households where >> there are members with different methods for accessing the computer using >> assistive technology, it is necessary to install two different access products on one computer. The software packages used in the area of low vision and blindness (Window Eyes, JAWS/Magic and ZoomText) utilize the video driver to pass information to and from the computer's operating system; in this case Windows XP. It is my understanding that the programmers have always used this method of accessing the operating system, but the changes in Windows XP have made it impossible for them to co-exist on the same computer and function independently. GW Micro has worked with Microsoft to develop a standard called the Device Chaining Manager (DCM), which identifies each product and allows them to share the same computer without overwriting another company's video hook. The DCM standard has been adopted by the companies listed earlier and will be incorporated in the latest release of their products. << Access Technology Newsletter - March 2003 ----- Original Message ----- From: "Wendy Sharpe" <w.sharpe@xxxxxxxxxxxxx> To: "Jaws" <jaws-uk@xxxxxxxxxxxxx> Sent: Thursday, January 25, 2007 11:20 PM Subject: [jaws-uk] JAWS PROGRAM QUERY > What is Display Chaining Manager? ** To leave the list, click on the immediately-following link:- ** [mailto:jaws-uk-request@xxxxxxxxxxxxx?subject=unsubscribe] ** If this link doesn't work then send a message to: ** jaws-uk-request@xxxxxxxxxxxxx ** and in the Subject line type ** unsubscribe ** For other list commands such as vacation mode, click on the ** immediately-following link:- ** [mailto:jaws-uk-request@xxxxxxxxxxxxx?subject=faq] ** or send a message, to ** jaws-uk-request@xxxxxxxxxxxxx with the Subject:- faq