I had similar problems. With my PC right next to my DIR-655 router, speed was good and it ran fine. Took my PC downstairs, where other laptops could connect to the wireless network, and this DWA-552 card could not even see the router. After trying the card in a couple PC's running Windows XP, and having the same problem, I decided to try another vendor card. I tried the Linksys Wireless-N PCI adapter, WMP300N, and success at last. This Linksys adapter even comes with a 5' antenna. I installed it like the forum's have been suggesting (not using the wizard, but using Device Mgr) and it came up first time, and saw my whole neighborhood. I don't know what is going on with DWA-552 cards, but it is nice to see there is another vendor's card works.