Just bought a new Windows 7 64-bit computer and discovered that it had inputs for only one of my two old VGA monitors. This adapter seemed the perfect solution. Installation was quick, the computer restarted as promised, and the display appeared on both monitors. Then both monitors flickered and went black. We waited and waited and waited, then rebooted after it was clear that nothing further was going to happen. The computer restarted with the image on the primary display only, and the blue light on the adapter was off. I right-clicked on the Safely Remove Hardware option and the computer froze. Nothing to do but restart. This time I was able to use Safely Remove Hardware and then moved the adapter to a different USB port. Still no blue light. I unplugged it, uninstalled and reinstalled the driver, then plugged it back in and restarted. This time it worked. I moved a few things onto the secondary display to see how the extended desktop worked, decided I didn't like the resolution, right-clicked to access Display properties and the computer froze again. Restarting generated a blue screen of death as soon as the secondary display came on. The next cycle of uninstalling and reinstalling found the computer freezing again, this time when clicking a link. After six rounds of freezing followed by blue screens of death upon restarting, I repackaged the adapter and returned it (Amazon have been brilliant with the speed of the return).
Possibly I received a faulty unit, but I see similar reviews from a those who had ordered the widescreen version of this, so at least I know I'm not alone.