Many Time Warner Cable customers (as well as others) are experiencing problems obtaining an IP address from Time Warner Cable routers (as well as other routers) while using Windows Vista. Typically the issue is that Windows Vista is unable to get an IP address which results in limited connectivity or no internet access, just local access.
Initially this error looks like a network adapter problem but this is not always the case in the Vista/Time Warner Cable scenario.
The reason this error occurs is because unlike XP, Windows Vista forces the use of the DHCP Broadcast Flag. Windows 7 uses a toggle switch to check for the feature and will disregard if it is not present. When a device does not support this feature as many of the Time Warner Cable routers (as well as others) don’t the result is the inability to get an IP address and subsequently outside internet access. It is not clear whether a recent ISP system update or Windows Vista update is the cause for the recent issue for Time Warner Cable customers but in either case the fix is outlined below.
To solve this problem you have to make Vista compatible with the Time Warner (or other) equipment by disabling the DHCP Forced Broadcast Flag for your networking devices. (you really only need to do it to the one you use to connect to the Time Warner (or other) router but doing them all is the simplest approach.
To do this you will need to edit the registry. You will have to go to Start then type in the search box regedit and you will see in the results regedit as a program. Run it to access the registry editor. (you must be logged in as an administrator)
In the left pane of the Registry Editor find the following registry subkey to see your network adapter settings:
You should see one or more folders or (GUID) subkeys here. As you highlight them you will see the contents of each folder on the right pane of the Registry Editor. Some folders or subkeys may have nothing in the right pane other than the word default, skip these for the ones that actually have settings established.
For each adapter find the following key in the right pane of the Registry Editor:
Right click this key and select modify. You will notice the value is set to (1) which is on. Change the value to (0) which is off and will disable the feature. Do this for all adapters under interfaces and on all of your Windows Vista computers.
Close the registry editor, reboot the computer(s) (to reload the registry). Once the computer is up it will likely still have limited connectivity so you will also need to reboot the Time Warner Cable (or other) router. Give it a minute to fully cycle (boot) and you should be back on line.
If this fix works for you please comment on this article.
If it does not work for you, you are having another issue and I would suggest bringing it in for a free diagnostic if you are local.