No Internet Connection (Wired or Wireless)

Had a laptop that would not connect to the internet.  Either wired or wirelessly it would not be able to get an IP address from DHCP.  I found this in the helpful Microsoft knowledgebase article 817571 (http://support.microsoft.com/kb/817571).  Essentially, the Windows sockets registry subkeys have become corrupted and must be replaced:

Method 1 exports the subkeys, then recreates them, other methods involve copying the keys from an operational, similar computer.

Use Registry Editor to export and delete the Winsock and Winsock2 registry subkeys, and then remove and reinstall TCP/IP on Microsoft Windows 2000 or  Microsoft Windows XP.   To do this, follow these steps.

Export and delete the corrupted registry subkeys

1. Insert a floppy disk in the floppy disk drive of the computer whose registry entries you are exporting.
2. Click Start,  click Run, type regedit,  and then click OK.
3. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Winsock
4. Do one of the following steps, depending on the operating system:
   • For Windows XP, on the File menu, click Export.
   • For Windows 2000, on the Registry menu, click Export.
5. In the Save in box, click 3½ Floppy (A:), type a name for the file in the File name box,  and then click Save.
6. Right-click Winsock, and then click Delete. When you are prompted to confirm the deletion, click Yes.
7. Repeat steps 3 through 6 for the following subkey:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Winsock2

   Note Each  .reg  file that you save must have a different name.

8. Right-click Winsock2, click Delete, and then click Yes.
9. Quit  Registry Editor.

Windows XP-based computer

Reinstall TCP/IP on a Windows XP-based computer

In Windows XP, the TCP/IP stack is a core component of the operating system. Therefore, you cannot remove TCP/IP in Windows XP.

1. Install TCP/IP on top of itself. To do this, follow these steps:
   1. In Control Panel, double-click Network Connections, right-click Local Area Connection, and then click Properties.
   2. Click Install.
   3. Click Protocol, and then click Add.
   4. Click Have Disk.
   5. In the Copy manufacturer’s files from box, type System_Drive_Letter:\windows\inf,  and then click OK.
   6. In the list of available protocols, click Internet Protocol (TCP/IP), and then click OK.
2. Restart your computer.

This did the trick for me.  I needed to reinstall the TCP/IP for both the LAN and wireless connections.

Wi-Fi in Windows 7

I may have posted about this, but, alas, I can’t remember (the whole point of this blog, I guess).  To keep Windows 7 (I suppose it may be the same in other Windows versions as well) from shutting off the wireless when “not it use”, do the following from a Tom’s Hardware forum:

Navigate to the control panel and open the Device Manager. Open the Network adapters section, right-click your wifi adapter and choose Properties. Navigate to the Power Management tab, uncheck allow the computer to turn off this device and set it to allow this device to wake the computer and then save the changes you made.

Alternatively, click on the wireless icon in the system tray and open the Network and Sharing Center.  Click on the wireless connection, click on Properties and then Configure.  Select Power Management and uncheck “Allow the computer to turn off this device to save power”.

Dis-allowing this is helpful in ensuring that students don’t lose their work when editing files from the file server.