0 Replies Latest reply on Nov 25, 2009 7:09 AM by Skibumtx

    "Windows 7 cannot obtain an IP address from certain routers or from certain non-Microsoft DHCP servers"




      Found this posted on the boards over at Microsoft - seems to be a likely candidate for why so many are having wireless connection issues.


      By the way, anyone know how to determine the GUID for my wireless adapter (as mentiioned in METHOD 5 Below)?




      From: wireless signal fades out
      Follow the methods listed below to troubleshoot the Wireless Router connectivity:

      Method 1. Please check that the router Firmware is up to date.
      Check at the Router's Manufacturer's website for Windows 7 compatible updated Firmware for it.

      Method 2. Make sure you have the upto date Network drivers:
      Update a driver for hardware that isn't working properly

      You can also perform these three troubleshooting methods:
      Method 3:
      Disable the IP Helper service:
      1. Hold the Windows key and type R, enter "services.msc" (without the quotes) and press Enter
      2. Scroll down to the IP Helper service, right click on it and select Properties
      3. In the dropdown box that says "Automatic" or "Manual", set it to Disabled and then click on "Apply"
      4. Then click on "Stop" to stop the service from running in the current session
      5. Click OK to exit the dialog

      Method 4:
      Please cross check if the WLAN AutoConfig is set to Automatic:
      1. Open the Start Menu.
      2. In the search line, type services.msc and press Enter.
      3. If prompted, click on Continue in the UAC prompt, or provide the administrator password to approve.
      4. Locate the service WLAN Autoconfig, Right click on the service and click on Properties.
      5. Next to Startup type, click on the drop down menu and select Automatic and click Apply.
      6. Click on OK.
      8. Close the Services window.
      NOTE: Restart the computer for the changes to the services to take affect.

      Method 5:
      Disable the DHCP Broadcast Flag:
      Link: http://support.microsoft.com/default.aspx/kb/928233
      Important: This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
      http://support.microsoft.com/kb/322756 (How to back up and restore the registry in Windows)
      Windows 7 cannot obtain an IP address from certain routers or from certain non-Microsoft DHCP servers
      To resolve this issue, disable the DHCP BROADCAST flag in Windows 7. To do this, follow these steps:
      1. Click Start, type regedit in the Start Search box, and then click regedit in the Programs list.
      If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
      2. Locate and then click the following registry subkey:
      3. In this registry path, click the (GUID) subkey that corresponds to the network adapter that is connected to the network.
      4. On the Edit menu, point to New, and then click DWORD (32-bit) Value.
      5. In the New Value #1 box, type DhcpConnEnableBcastFlagToggle, and then press ENTER.
      6. Right-click DhcpConnEnableBcastFlagToggle, and then click Modify.
      7. In the Value data box, type 1, and then click OK.
      8. Close Registry Editor.
      By setting this registry key to 1, Windows 7 will first try to obtain an IP address by using the BROADCAST flag in DHCP Discover packets. If that fails, it will try to obtain an IP address without using the BROADCAST flag in DHCP Discover packets.

      Hope it helps. 

      Thanks and Regards:
      Shekhar S - Microsoft Support.