# Cannot see other computer (intermittently)



## bubka (Aug 7, 2011)

I am running a laptop (Windows 7) and a desktop (Windows XP SP3), with the laptop connected wirelessly and the desktop connected by ethernet cable to a Linksys modem / router.

Both computers can always connect to the internet.
The laptop can (almost always) print from the usb printer connected to the desktop.
Only on about 30% of occasions can I see the other computer in Windows Explorer or the equivalent, and therefore cannot access all the files.

I can usually ping the other computer by ip and get a reply.
I can rarely ping the other computer successfully by name unless I ping by ip first.

Here is the really strange part: I can usually access the files on the desktop through Word or Excel, because the default folder is Shareddocs on the desktop, and it is visible in File\Open. So the laptop knows the desktop is there but doesn't display it.

Over a large number of trials, whether the ZoneAlarm Free firewalls are on or off makes no difference. 

All the usual sharing permissions have been enabled.

I know the "usually" and "rarely" make it more difficult to diagnose, but that's life.
Can anyone help please?


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## 2xg (Aug 5, 2009)

Hi bubka,

Might be a good idea to uninstall Zone Alarm completely if you have not done it yet. Your Windows built-in firewall shd do a great job as well.
Pls use Revo Uninstaller to completely remove Zone Alarm.
Download Revo Uninstaller Freeware - Free and Full Download - Uninstall software, remove programs, solve uninstall problems

If uninstalling ZA didn't help, make sure that you have the latest driver for the Wi Fi adapter. 

An update will be appreciated.


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## bubka (Aug 7, 2011)

Hi 2xg,
Thanks for your reply.
I am loathe to uninstall ZoneAlarm without an indication of why it might have an effect on the networking. This is just to avoid having to reestablish all the permissions on both machines afterwards.
I have already updated the router driver and the wireless adapter (in the laptop)- I should have said that.
The only thing that seems to have a beneficial effect is to reboot the router. Again I am loathe to do that often, as it lowers my ADSL ip profile, and I am now running below half-speed broadband as a result.


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## 2xg (Aug 5, 2009)

Uninstalling ZA will not affect anything related to your network only the computer where ZA is installed. It might fix the issue. You'll have to take the risk when you are troubleshooting. 


> I am loathe to uninstall ZoneAlarm without an indication of why it might have an effect on the networking. This is just to avoid having to reestablish all the permissions on both machines afterwards.


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## bubka (Aug 7, 2011)

I meant that I couldn't see why uninstalling ZA would have a beneficial effect on the networking, ie solve my problem.
However, I have uninstalled it from both computers, and the situation is virtually the same as before (bearing in mind that the symptoms varied slightly, anyway).
I can ping desktop by ip , and then by name. I cannot ping laptop by ip or name. I can get internet from both m/cs. I can use printer from both. I can see / edit / save sharedocs files on desktop from the laptop by calling them up from Word / Excel. I cannot see / access the other computer in My Network Places.


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## 2xg (Aug 5, 2009)

Firewall and Security Software have been the No. 1 suspect on computers in network not able to communicate. I've seen and dealt with them, an FYI....:grin:

Next task, pls. provide an *ipconfig /all* output of all the computers in your network.
Click on Start => in run or search box type cmd, choose run as Admin and press enter. Open up a command prompt then Copy and Paste these ipconfig /all >c:\ipconfig.txt . Please attach the .txt file to be found in your Local Disk 'C' on your next post.


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## bubka (Aug 7, 2011)

Sorry, 2xg.
I can run a ipconfig / all and see the results, but I don't understand how to copy them into a text file.
I have "screendumped" them into Word documents, which are attached - I hope.
If this isn't good enough, please let me know how to do what you want.
Thanks.
View attachment Desktop.doc


View attachment Laptop.doc


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## old.jeeper (Aug 9, 2011)

Since you can ping by IP address but not by name, that sounds like a DNS issue to me.


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## 2xg (Aug 5, 2009)

Thanks a lot bubka. The only thing that I need to you verify for me is the DNS Addresses. Are you using your ISP's? Do you have your DNS setting auto and not manually configured in the LAN/Wireless settings?


bubka said:


> Sorry, 2xg.
> I can run a ipconfig / all and see the results, but I don't understand how to copy them into a text file.
> I have "screendumped" them into Word documents, which are attached - I hope.
> If this isn't good enough, please let me know how to do what you want.
> ...


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## Wand3r3r (Sep 17, 2010)

How to do a ipconfig /all

Go to programs/accessories and command prompt
right mouse click on command prompt and choose run as admin
in the black box type ipconfig /all
right mouse click on the title bar and choose edit then select all
then right mouse click and choose edit and select copy
paste into a post here for review

"I cannot ping laptop by ip or name"

Then you still have a firewall engaged or another program installed that does similiar. Windows firewall shut down? Any antivirus/malware checker on here?


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## bubka (Aug 7, 2011)

2xg,
The DNS settings are set to automatic, on both machines. 

My broadband supplier's (PlusNet) DNS servers are:
212.156.13.49 - primary
212.156.13.50 - secondary
212.156.6.9 - optional tertiary


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## 2xg (Aug 5, 2009)

As Wand3r3r said pls check for any other Spyware or Security Software installed from the laptop. Something is still blocking if unable to ping.
Any expired Anti Virus software installed? This might also cause an issue.


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## Wand3r3r (Sep 17, 2010)

Please provide the requested ipconfig /all output. Thx


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## bubka (Aug 7, 2011)

Wand3r3r,
The ipconfig output files are attached to my message of 8 Aug above.

2xg,
There is no spyware on laptop, only MSE antivirus (up to date). Today I can ping the laptop by ip but not by name.


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## 2xg (Aug 5, 2009)

Try pinging the IP Address of the problematic computer, open up a command prompt and type for ex....*192.168.1.11 -t* press enter. Your computer's IP will be different than my example. See if it's timing out in between and report back.


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## bubka (Aug 7, 2011)

Symptoms are the same as yesterday. I can ping laptop by ip without it timing out (although all last week it timed out). I cannot ping by name - it "could not find host".
In the other direction, I can ping the desktop by ip, and by name (but only after pinging by ip).
This morning the laptop would not accept the desktop's printer as "ready", until I had pinged the desktop, then the printing worked.
As I said, the problems are intermittent.

If you can solve it, I shall praise you to the skies.


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## 2xg (Aug 5, 2009)

Try replacing the problematic network adapter, they are very reasonable, Wi Fi or NIC.


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## bubka (Aug 7, 2011)

I should have tried this before, but have been busy with other things:
I turned off wireless connection on laptop, and connected to router by ethernet cable.
Result: everything worked perfectly and computers showed in Network Neighbourhood immediately. On reverting to wireless, the problem came back.
So, if the wireless network adapter is playing up, how can I still connect to the desktop's printer and access its files through Word?
I shall try a repeat tomorrow, in case this is an intermittent good result.

Incidentally, the laptop is within warranty. Would you consider that this is a "manufacturing" problem?


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## 2xg (Aug 5, 2009)

A wired network is always doable than wireless. Another option to look at is a NAS solution. Have a read here: Network Attached Storage (NAS) | | Tech Support Forum


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## bubka (Aug 7, 2011)

A further update: reinstalling the laptop wireless network adapter driver had no effect.
Switching the router off for 10 seconds restored all the connections.
I shall try reinstalling the router driver, as I believe the problem lies in this device.


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## Wand3r3r (Sep 17, 2010)

There is no such thing as a router driver.

On the other hand there is router firmware which is installed on the router to correct software issues. You would go lookup your model router on the manufactures web site and see if there is a firmware update for it.

Your files don't open for me. They are blank word docs.


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## bubka (Aug 7, 2011)

Thanks Wand3r3r.
I found out about router firmware yestaerday. Mine is the latest version.
I don't understand about the files. I can open them from this website.


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## bubka (Aug 7, 2011)

This will probably be my last post on this subject. I seem to have found a workaround, and discovered another vagary of Win 7 / Win XP networking.
If I search for the desktop computer by name, it will only (and always) find it if I ping first by ip and then by name. One of the items found is the shareddocs folder shortcut, which I can then open. Immediately, the Windows Explorer window recognises the desktop's existence.
However, if I open up another Windows Explorer window, the desktop is not there!

I have booked into the local asylum.
Thank you for your responses.


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