I am using static IP on my LAN. Whenever I unplug the network cable. My LAN will become sleep mode and my static IP gone. When I used IPconfig to check my Ethernet Adapter Local Area Connection, the Media State is Media disconnected. I search everywhere to enable my Ethernet when cable is unplugged, and I found out that the power management for Network Devices in Windows 7 has a feature called Lower Power on Media Disconnect . and i also found the keyword "DeviceSleepOnDisconnect ". Can I off this Lower Power on Media Disconnect feature? or set the DeviceSleepOnDisconnect value to 0 (default is 1)? By the way, I am using Windows 7 64bit, Lenovo G450 laptop, Broadcom NetLink NIC.

Don't confuse 2 things here: 1) when you unplug the cable, the adapter states "media disconnected". This is by design and only configurable through registry. http://support.microsoft.com/default.aspx/kb/239924 shows how to do this. 2) power saving for the NIC. This is a feature to lower the powerconsumption of your computer by putting the device in sleepmodes if the media is disconnected or the pc enters sleepmode/standby. DeviceSleepOnDisconnect refers to this feature. You should configure this using the GUI: driverproperties of the NIC, advanced TAB. You can also find some related settings via power options in control panel. Refer to http://technet.microsoft.com/en-us/library/ee617165%28WS.10%29.aspx for more info

Thank for you answer. I now understand the different between these two. I tried to set the "DisableDHCPMediaSense" to 1 at HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters and reboot... it still shows "Media disconnected". i check the advance setting on the NIC, no seen something related to power options, i only found the checked box "Allow the computer to turn off this device to save power" at the Power management tab. But nothing happen l..... :\ hmm...

I did some searching on this and it seems that since Vista (and probably the rework op teh network configuration part) this method is no longer valid. I found another post (http://social.technet.microsoft.com/Forums/en-US/itprovistanetworking/thread/78837cc8-b101-4236-906a-f09f0c442221 ) which recommends to use the netsh command to set the parameters, but I tried this on my Windows 7 machine, and no avail :( edit: http://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/TCPIP_Reg.doc is the info Microsoft provides on the changes in the registry network configuration (Vista, 2008) This documentation states the same registry key as mentioned before!

Similar concern is in the following thread. We have already reported it to proper department. Windows 7 DisableDHCPMediaSense and routing tableArthur Xie - MSFT