I'm looking for help with a Vista Home Premium laptop that has trouble accessing any resource on our home network, but accesses the Internet just fine.
The set-up is this: The Vista laptop and a MacBook Pro connect wirelessly to the router-modem. A Synology DS212j NAS drive has a wired connection to the router-modem. Devices on the local network are always referred to by IP address, so this cannot be a DNS issue.
The MacBook Pro connects reliably to the NAS via AFP (network shared folders), SMB (network shared folders) and HTTP.
The Vista laptop connects to and browses sites on the Internet without any problems.
It can log into the NAS via SMB and list the shared folders (so there is nothing wrong with the log-in credentials), but when it tries to open any of the folders Explorer just hangs with the spinning cursor for several minutes and then says "\192.168.1.64\shared\Photos is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. The specified network name is no longer available."
It can ping the NAS successfully.
If I try to open the NAS drive's web interface, the browser just hangs. This is the same with IE, Firefox and Chrome. (There is no proxy.)
I can log into the NAS drive with FTP and navigate directories, but when I try to list the contents of a directory with more than a handful of entries, the ftp client hangs.
I set up a website on the MacBook. The Vista laptop was able to load some of the pages, but loading any of the images was very hit and miss. Images embedded in HTML pages never worked no matter how many times I reloaded the page, but when I linked directly to the image it did load (though several attempts were sometimes needed).
I tried all of this with the Windows Firewall turned off, and with AVG turned off. That made no difference.
I'd really appreciate any suggestions anyone can make. The fact that the Vista laptop has trouble with HTTP and FTP as well as SMB connections suggests to me that this is a problem at the TCP level or below. But don't forget it accesses sites outside the LAN with no problems.
New 7 Oct
The Vista laptop has no trouble reaching the NAS drive if I disable the wireless NIC and connect by wired Ethernet.
(Remember also that WiFi works fine when accessing resources outside the LAN. It's only on the LAN that the problem exists.)