Troubleshoot network connection problems

To troubleshoot a network connection problem, try these steps first:

  1. Open Network Diagnostics by right-clicking the network icon in the notification area, and then clicking Diagnose and repair.

  2. Make sure that all cables are properly connected.

  3. If you're trying to connect to another computer, make sure that computer is on and that you have enabled file and printer sharing on your network. For more information, see Networking home computers running different versions of Windows.

  4. If the problem began after you installed new software, check your connection settings to see if they have been changed.

    To check connection settings

    1. Open Network Connections by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.

    2. Right-click the connection, and then click Properties. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

If these steps don't solve the problem, look for a specific problem in the following table.

Problem
Possible solutions

Can’t connect to other computers or share files and printers on a home network

  • Make sure network discovery is turned on.

    To turn on network discovery

    1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

    2. If network discovery is off, click the arrow button Picture of the arrow button to expand the section, click Turn on network discovery, and then click Apply. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    Note

    • Network discovery is off by default for Public networks. Changing a network location type to Private is another way to turn on network discovery. To learn how to change a network location type, see Choosing a network location.

  • Make sure you have shared the files or printers.

    To share files and printers

    To share files: Click the arrow button Picture of the arrow button to expand the File sharing section, click Turn on file sharing, and then click Apply. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
    To share files using the Public folder: Click the arrow button Picture of the arrow button to expand the Public folder sharing section, click either Turn on sharing so anyone with network access can open files or Turn on sharing so anyone with network access can open, change, and create files, and then click Apply. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
    To share a printer: Click the arrow button Picture of the arrow button to expand the Printer sharing section, click Turn on printer sharing, and then click Apply. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    Do these steps on your computer and on any network computer running Windows Vista that you want to connect to.

  • If password protected sharing is enabled, you have two options.

    More information

    If password protected sharing is enabled, you can create identical user accounts on all computers in the workgroup (recommended). For more information, see Create a user account. Or, you can turn off password protected sharing.

    To turn off password protected sharing

    1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

    2. Under Sharing and Discovery, click the arrow button Picture of the arrow button next to Password protected sharing.
    3. Click Turn off password protected sharing, and then click Apply. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

  • Make sure the computer that you want to connect to has at least one shared folder.

  • Make sure all computers are in the same workgroup. See Join or create a workgroup.

  • In addition to enabling file sharing, make sure you set sharing properties on the folder or printer you want to share.

    More information

    File and printer sharing is a two-part process: first you need to enable sharing as described above, and then you need to set sharing properties on the item itself or move it to the Public folder so that other people can access it. For more information, go to File and Printer Sharing in Windows Vista on the Microsoft website‌.

  • Go to the website of your router manufacturer to download and install the latest firmware for your router.

Can't connect to a home network (wireless connection)

  • Make sure the router and modem are turned on.

  • If you're using a laptop, make sure the wireless switch on the front, side, or back edge of the laptop is turned on.

  • If Windows doesn’t detect a network that you think is in range of your computer, open Help and Support and search for "Troubleshoot problems finding wireless networks."

  • Make sure the network adapter is working correctly.

    To verify that a network adapter is working correctly

    You must be logged on as an administrator to perform these steps.

    1. Open Device Manager by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Device Manager. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    2. Expand the Network Adapters section, right-click your adapter, and then click Properties.

    3. Under Device status, check to see that the device is working properly.

  • Download and install the latest version of the network adapter driver from the manufacturer's website.

  • Clear the DNS resolver cache. For more information, see DNS (Domain Name System): frequently asked questions.

Can't connect to a home network (wired connection)

  • Make sure the router and modem are turned on.

  • Make sure that the Ethernet cable is inserted into the network adapter in your computer.

    Illustration of an Ethernet cable
    Ethernet cable
  • Make sure the Ethernet cable is not defective. Test this by using a different cable that you know works properly.

  • Make sure the Ethernet cable is connected to the correct port on the router.

    More information

    The Ethernet cable from your computer to the router should not be connected to a port marked "uplink," "WAN," or "Internet." Some routers disable the port next to the uplink port, so try using a different one.

  • There might be problems with your network adapter. Check your local area network (LAN)connection.

    To check your LAN connection

    Open Network Connections by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.

    The network icon Picture of the network icon changes depending on the status of the LAN connection, and there is information if the adapter isn't working correctly. Also, if a LAN cable is unplugged, a status icon is displayed in the notification area.
  • Make sure the network adapter is working correctly.

    To verify that a network adapter is working correctly

    You must be logged on as an administrator to perform these steps.

    1. Open Device Manager by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Device Manager. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    2. Expand the Network Adapters section, right-click your adapter, and then click Properties.

    3. Under Device status, check to see that the device is working properly.

  • Download and install the latest version of the network adapter driver from the manufacturer's website.

  • Clear the DNS resolver cache. For more information, see DNS (Domain Name System): frequently asked questions.

Can't remember network key

If you've forgotten your network key, and there is no one else who knows it, you'll need to set up your wireless router again. See Set up a wireless router.

Network connection is intermittent (periodically disconnects)

  • Turn off the power-saving option in the network adapter's properties.

    To turn off the power-saving option

    1. Open Network Connections by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.

    2. Right-click the connection, and then click Properties. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    3. On the Networking tab, click Configure.

    4. On the Power Management tab, clear the Allow the computer to turn off this device to save power check box, and then click OK.

Network connection is too slow

  • Go to the manufacturer's website to check for more recent drivers for your network adapter.

  • Make sure you have the latest Windows Vista service packs installed.

  • Try turning off autotuning.

    To turn off autotuning

    1. Click the Start button Picture of the Start button.
    2. In the Search box, type command prompt.

    3. In the list of results, right-click Command Prompt, and then click Run as administrator. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    4. Type netsh interface tcp set global autotuninglevel=disabled, and then press ENTER.

    5. Restart your computer.

    (To turn autotuning back on, type the command netsh interface tcp set global autotuninglevel=normal, and then press ENTER.)

  • Make sure the capacities of the router and the network adapter are compatible.

    More information

    For example, if the router is 10/100, but the network adapter is gigabit Ethernet, the network will transmit at the lower speed. You will need to replace the slower device to get the higher speed.

  • If you’re using a wired connection, try modifying the flow control setting.

    To modify the flow control setting

    1. Open Device Manager by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Maintenance, and then clicking Device Manager. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

    2. Right-click the network adapter, and then click Properties.

    3. Click the Advanced tab, and then click Flow Control.

    4. Under Value, select Rx and Tx Enabled (in some cases, this might be called Auto or Rx/Tx Pause), and then click OK.

Can’t connect to a workplace network from home (or another location) using a VPN connection

  • Make sure you typed the virtual private network (VPN) server name exactly as provided by your network administrator.

  • Make sure you have an active Internet connection.

  • If your modem is external, make sure that the modem power is turned on.

  • Check your encryption settings.

    More information

    If you receive the message “The local computer does not support encryption” (error 741), it’s possible that the encryption that your computer uses doesn’t match the encryption used by the VPN server. Change the encryption settings so that your computer uses the recommended setting of 3DES.

    To change encryption settings

    1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.

    2. Click Connect to a network.

    3. Right-click the VPN connection, and then click Properties.

    4. Click the Security tab, click Advanced (custom settings), and then click Settings.

    5. In the Advanced Security Settings dialog box, under Data encryption, select Maximum strength encryption (disconnect if server declines), and then click OK twice.

    6. Click Connect to try connecting again.

  • Contact your network administrator for assistance.

    More information

    There are a number of other possible problems, including insufficient connection and domain permissions, certificate problems, Winsock proxy client problems, Domain Name System (DNS) resolution problems, server problems, and problems related to software provided by your workplace. Contact your network administrator for assistance with these problems.

Can't set up an incoming connection

To set up an incoming connection

  1. Open Network Connections by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Network and Internet, clicking Network and Sharing Center, and then clicking Manage network connections.

  2. If you don't see the File menu, press ALT.

  3. Click File, and then click New Incoming Connection. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

Can't share the root of a drive

To share the root of a drive

  1. Open Computer by clicking the Start button Picture of the Start button, and then clicking Computer.

  2. Right-click the drive, and then click Share.

  3. In the drive properties dialog box, click Advanced Sharing. Administrator permission required If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

  4. In the Advanced Sharing dialog box, select the Share this folder check box, type a share name, and then click OK.

Notes

  • You cannot share the root of a drive with a dollar sign following the drive letter as in previous versions of Windows. For example, you cannot share the root of your C drive as "C$," but you can share it as "C" or any other name.

  • For security reasons, we recommend that you share only selected folders, rather than the entire drive.

There's a duplicate IP address on the network

I need advanced information about network troubleshooting