Fails to connect to network on boot, have to reset network adapter

Frequently (but not always...) when I start my Vista Business computer, it
won't connect to the Ethernet (not wireless) network. Ipconfig shows just
blanks against the network adapter as follows:
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Default Gateway . . . . . . . . . :

The only way I've found to get back online is to:
1. Go to Network Adapter Diagnose and Repair.
2. Click Automatically get new IP Settings for the network adapter "Local
Area Connection" (I would click Reset the Network Adapter, but annoyingly it
doesn't appear at this stage).
3. Wait till it tells me it didn't fix the problem (about 50 seconds)
4. Click Reset network adapter "Local Area Connection", which now _is_ in
the dialog box.

This is extremely annoying.

Why is this happening? It usually happens on my work network. It usually
does not happen on my home network. Both use DHCP.

Is there a fix?

If there's no fix, how can I automate the above repair process? I've tried a
number of techniques without success... Is there some script command in WSH
that will reset the network adapter? Or can I just automate the click
sequence described above in some way?

Thanks - Rowan

Have you checked if there are a new drive for the NIC and a new firmware for
the router?

I've checked the NIC. I can't check the router because it is controlled by
our IT people, but other users don't seem to be having this problem, so it
can't be that, can it?

Rowan

Next time it happens, try starting a command window and do an
ipconfig/renew. See what results you get.

Since you have an IT crew, ask them to sort it out for you. That's what
they are paid to do.

Nice idea, but they don't approve of our use of Vista and refuse to support
it - so I'm on my own on this I'm afraid... I think they've just about
caught up with XP...

I've tried that - it doesn't help.

What exactly does the Reset Network Adapter command on the Windows Network
Diagnostics dialog do? That seems to be the only thing that helps. Can I
access this command in a command window, or using Windows Script Host, or
using Devcon? I've tried to find out how to do all of these things, and so
far I've failed.

And why does the Reset Network Adapter command not appear in the Windows
Network Diagnostics dialog until I've tried to renew the IP?

Thanks for your help!

Rowan

To be more precise, if I do ipconfig /renew, after a long pause I get:

C:\Windows\system32>ipconfig /renew

Windows IP Configuration

An error occurred while renewing interface Local Area Connection : unable to
contact your DHCP server. Request has timed out.
No operation can be performed on Bluetooth Network Connection while it has
its media disconnected.
No operation can be performed on Local Area Connection 2 while it has its
mediadisconnected.
An error occurred while renewing interface Local Area Connection 4 : unable
to contact your DHCP server. Request has timed out.
No operation can be performed on Wireless Network Connection while it has
its media disconnected.

C:\Windows\system32>

This happens whether or not I've done an ipconfig /release beforehand.

So you're actually not connected in any meaningful way. The reset
command you are using is doing some equivalent to an enable/disable on
the adaptor and causing Vista to restart it. Or, from another
direction, I bet you could go in and disable the adaptor, then enable
it, and get similar results.

There's a chance that this KB might help:
http://support.microsoft.com/kb/928233

Thanks for this suggestion. The KB article looked promising, but the fix
suggested there has not solved the problem. I've now restored my registry to
before the fix. I notice that my registry already has in it for this network
adapter:

DhcpConnDisableBcastFlagToggle=1
DhcpConnForceBroadcastFlag=1

I don't know, but at first sight these settings appear incompatible with the
setting suggested in the KB article, viz:

DhcpConnEnableBcastFlagToggle=1

Does anyone understand exactly what these settings do? If I have all three
of these settings in my registry, what's going to happen? What do I need to
do to disable the use of the DHCP Broadcast Flag - if (as suggested in the
KB article) this is the source of the problem?

[racc]

Hello Rowan,

I have the same problem as you do with my new lenovo running vista x64 business. The solution I use now is the same, restarting the intel wifi link form the manage netwoork connections pannel. Did you find any solution that really makes sense?

Thanks in advance,

racc