I was looking at my network in Windows Explorer, or whatever it is now called in Windows 7, and added the column"Discovery Method." The two drives that the other computer cannot see are discovered on my computer with Netbios. I checked the adapter settings for both computers and they appear identical. Network and Sharing Center Change -> adapter settings -> [the active wireless adapter] -> Internet Protocol Version 4 (TCP/IPv4) -> Properties -> General -> Advanced -> WINS. The Netbios setting for both computers is "Default: Use NetBIOS setting from the DHCP server. If static IP address is used or the DHCP server does not provide NetBIOS setting, enable NetBIOS over TCP/IP." I switched the offending computer to "Enable NetBIOS over TCP/IP" then I disabled the adapter and re-enabled it. No difference. I still could not access the NAS by name.