John, Thank you for your response. You are right on target. I appolgize for my clumsiness in trying to reply to your guidance. Anyway I think I've narrowed this down to an IRQ "sharing" issue for the Sierra Wireless 860 Card. It is a 16-bit card that uses dedicated resources and the Dell BIOS likes to share IRO resources. Dell has updated the BIOS and Sierra has provided Vista Drivers. Duel Systems has RMA'd the Adapter and all of the vendors involved Dell, Microsoft, Dual Systems, Sierra, and Cingular(at&t) have been very helpful built have not provided a solution thus far. They all claim compatibility with Vista but I guess in today's multi-vendor environment no one can be sure.....So far I can use 32-Bit devices with no problem but not the Sierra Card. Any other advice is greatly appreciated. .