One computer on my LAN has problems communicating with peers

I have a problem with one of the four Win7 Pro computers on my home LAN. (See attached screen prints for some views of the network.)

The problem child is a computer named KenThink (a ThinkPad T410). In general, it works fine on the LAN: It connects OK, accesses the internet with no trouble, and in some ways it communicates well with peer devices on the LAN. But it has the following specific disabilities (which the other computers on the LAN don't have):

1. I just got a new networked printer (Brother MJC-J985DW). When I try to install it on KenThink, the printer installation software can't find the printer on the network, either as a wireless or as a wired printer. Even if I supply the printer's IP address manually, it doesn't work. Another weird point: If I set up the printer as a shared printer on another computer, I can find and install it as a networked printer through the Windows "Devices and Printers" window.
2. Another computer on the LAN, called KenDell, is set up to sync its data files over the LAN with KenThink, using an app called SyncBack SE. Intermittently, the synchronization can't be done because SyncBack can't find KenThink.
3. Sometimes, KenThink can't see KenDell via Windows Explorer in the Homegroup and/or Network. (See screen shot 3 for an example.) And sometimes the other computers can't see KenThink, though they always can see one another.

None of the other computers (including Suzy, another identical ThinkPad T410) have any of these problems, and aside from these problems, KenThink works fine on the LAN.


I'm hoping that the specificity (and the weirdness) of the symptom pattern will point to a specific (and hopefully fixable!) piece of KenThink's networking that is to blame.


~ Thanks in advance for your help!
~ Ken

You are using 2 switchs are they switchs or hubs there is a difference. Often these problems are down to homegroups and can be solved by removing homegroups. Homegroups use ipv6 and as such create extra traffic plus some devices cant pass ipv6 as at the present time its not used. Has all pc got network discovery turned on and all set to home network make sure all are the same

Samuria, thanks for your input, and I apologize for my long delay in responding. Here are my responses to your suggestions:

1. Yes, both of my "switches" really are switches, not hubs.
2. Yes, on the "Control Panel | Network and Sharing Center | Advanced sharing settings" panel, all the computers have "Network discovery" (and all the other sharing settings) turned on and set to the most permissive settings. Is this the setting that you are talking about, or is there another setting someplace else that I should be looking at?
3. I don't understand homegroups. Ever since I started using Windows 7, I have just enabled my LAN's homegroup, enrolled all my computers in it, and left it at that. So I'm afraid to remove the homegroup until I understand a bit more about it. Specifically: If I remove the homegroup, could that break anything else? If it did, could I reinstall or re-enable the homegroup? And how do I "remove" the homegroup - is that done just by selecting "Leave the homegroup..." on each computer? or is there some command that removes the homegroup itself?

~ Thanks again
~ Ken

Run this tool on a couple of problem one and see if it sees the pcs NetBScanner - NetBIOS scanner if you open a cmd prompt on each pc type ipconfig /all is netbios running on all pcs

Its simple to remove homegroup How To Disable or Enable the Homegroup Feature in Windows 7

Well, I'm baffled and delighted . Tonight, all of the problems that motivated this thread suddenly seem to be resolved! My problem computer, KenThink, can now connect to the network printer, sync with its mates, and see (and be seen by) all the devices on the LAN. I'm baffled because I don't know why all these problems have vanished (hopefully for good). It certainly isn't anything I deliberately did to fix them.

Samuria, just for the record, here are my responses to your latest suggestions:

samuria said:

Run this tool on a couple of problem one and see if it sees the pcs NetBScanner - NetBIOS scanner

Yes, everybody sees everybody. (Nice little tool!)

samuria said:

if you open a cmd prompt on each pc type ipconfig /all is netbios running on all pcs

Yes.

samuria said:

Its simple to remove homegroup How To Disable or Enable the Homegroup Feature in Windows 7

Those instructions look straightforward. Hopefully, due to the above miracle, I'll never have to use them!

~ Thanks again Samuria!
~ Ken

When you try and connect locally Windows asks the master browser which can be any of on the network if that isn't up-to-date it won't find it the scan creates traffic which will update master browser it should show in the results which of is the master