Randomly drops network connection

chev65 said:

It could just be a problem with the network adapter or the motherboard on this particular machine.

Intermittent connection problems aren't easy to diagnose. I'm also not so sure that the server isn't part of the problem with IPv6 missing and all. Something seems to be disconnecting this machine from the DHCP server from what I can see here.

Tell me about it. They are the worst.

The network adapter is on-board the M/B. Originally the M/B went back to the manufacturer and was deemed no fault found. Even though this was the case, this machine has had all of its hardware swapped for new parts to try and figure out what is happening, but to no avail.
Yes I agree that even though the hardware has been swapped, there could still be an issue with the new hardware, as I have had this in the past, but I do not think that this is the case in this situation.

I would think it was the server to, if all other machines we are building had the same issue, but they dont. Everything we have built before this problem system and after have all been ok. And If it was our server, why did it exhibit on our clients server 1st, who is running IPV6?

It maybe a case of dumping the system and specing up a new system with different hardware. Or alternatively, shipping it back to client as there is no real issue, that can be identified with the hardware, so it is deemed as a software fault, which looks like it lies within Windows 7.

17 Years in I.T. and never have I found such a frustrating problem.

chev, if you have any other suggestions. that would be greatly appreciated, but if you want to wash your hands of this, just say? It's not an issue and I can completely understand how difficult it can be to diagnose something from somebody else's descriptions.

Again, I very much appreciate your assistance on this.

Additional. It seems that from a powered off state, it is fine. If a Restart is issued, the network connection is lost. dont know if this gives anyone any ideas, but at the moment, anything is worth mentioning.

Sibuy said:

Additional. It seems that from a powered off state, it is fine. If a Restart is issued, the network connection is lost. dont know if this gives anyone any ideas, but at the moment, anything is worth mentioning.

Have you tried going into Device Manger, right click the connection, choose properties, and go to the Advanced tab, you can try making some adjustments there to see if you can get the connection to remain stable though it's hard to say which setting might have an effect.

You can also try the power management tab and turn off the power saving feature just in case.

Reinstalling the driver for this connection is another option.

chev65 said:

Sibuy said:

Additional. It seems that from a powered off state, it is fine. If a Restart is issued, the network connection is lost. dont know if this gives anyone any ideas, but at the moment, anything is worth mentioning.

Have you tried going into Device Manger, right click the connection, choose properties, and go to the Advanced tab, you can try making some adjustments there to see if you can get the connection to remain stable though it's hard to say which setting might have an effect.

You can also try the power management tab and turn off the power saving feature just in case.

Reinstalling the driver for this connection is another option.

Speed & Duplex - Set to Auto Negotiation = Problems
- Set to 100Mbps Full Duplex = works on every restart and shutdown/restart

But that still does explain what in Hades is happening on this machine compared to the other 29, which run fine on 'Auto Negotiation'.

Been a while since I posted as I thought I had got to the bottom of it.

I upgraded to all the latest drivers, Windows updates and in doing so discovered that with certain Windows updates would cause the problem. I avoided these updates (cannot remember what they were) and the system remained stable. I returned it to my client for him to discover he had the same issues again. After a summer break (education environment) he returned and tried to rectify the issue, but to no avail.

I have got the system back. Now am back to the beginning again. The strange thing is that I have 3 machines now doing very similar things, one is this one, the 2nd is a system that does lose the network on occasions but more of a worry is that the Windows installation seems to corrupt and on the occasional restart, asks for a Windows repair/restore. The 3rd is just a system that I have put together here to replicate the 1st system. All new hardware and fresh install of Windows 7. This also loses the network interface, although it shows it in device manager as working properly. All the problems always seem to occur after several restarts of the systems and also after Windows 7 updates have been done. If no updates are done, it stays stable. One thing that is a link to all these machines is that they all use Gigabyte motherboards (1 model in 2 of the systems and another model in the 3rd), the 3rd being the system that seems to corrupt it's Windows installation.

As always, have trawled the web trying to find any clues to what is causing these issues, but nothing I do seems to rectify the problem.

Any assistance would be greatly appreciated.

I am also experiencing problems with Windows 7 clients that suddenly drop their network connections and then cannot obtain a DHCP address.
Static IP is not an option (even though it works).
Several things seem strange:
- why does the workstation drop its connection suddenly? the leases are 90 days (if you can believe that) and nowhere near the half-way renegotiation.
- why do the workstations assign themselves 169.254.0.0 addresses when they have an ethernet connection and a DHCP server is available?
- why doesn't the Windows 7 DHCP client simply re-use the old address until it can contact a DHCP server?

I am suspicious of old network hardware (old Cisco switches) but things were working well until a few months ago. Is it a Windows 7 DHCP client issue?

Very frustrating.