Households are increasingly becoming multiple-PC homes. And as people add extra PCs to a home, they naturally want to share files between those systems. Typical multi-PC households also tend to have different operating systems; you may have a business laptop still running Windows XP, for instance, as well as an older media-center system using Vista and a Windows 7 computer that serves as a shared resource or specializes in gaming. Getting such disparate machines to talk to one another can be daunting.

In this article, we’ll examine how to troubleshoot some common Windows networking problems. Let’s start with basic connectivity troubleshooting.
Connecting to Your Network

You’ll typically have network-connection issues when you fire up a new computer or upgrade to a new version of Windows. The lack of a network connection has no single cause, so here’s a look at several potential problems and solutions.

Problems after upgrading Windows: Installing a new version of Windows on your system can wreak havoc on network connections. You may encounter different issues, depending on whether you upgraded or performed a clean install.

If you’ve upgraded from Windows Vista to Windows 7, it’s possible that you’ll simply need to reinstall the drivers for your networking hardware; that is more often the case if your connection is Wi-Fi rather than wired. The best approach is to download the new drivers from the Website of the motherboard or system manufacturer prior to performing the OS upgrade–but if you forgot to do that, the driver CD that came with your system or motherboard will very likely have drivers that work, even if they aren’t the most current versions.

IPv6 versus IPv4: I’ve run into this bizarre problem several times with new system installs. IPv4 (or IP version 4) is the Internet protocol addressing system most commonly used today. You may have seen articles proclaiming that the world is running out of IP addresses. Those are IPv4 addresses. The new system is IPv6, but it still isn’t in common use.

My main production PC and my Windows Home Server were both running only IPv4. A new Windows 7 install, which I performed on one of the systems, implements both IPv6 and IPv4. You would think that a machine running both the IPv6 and IPv4 protocols could connect to a system running only IPv4, but for whatever reason, that wasn’t the case: The PC running both protocols would simply not connect to the one running only IPv4. At first, I simply deleted IPv6 from the new system. After this problem occurred several times, I wised up–and all my systems are now running both IPv6 and IPv4.

Laptop fails to connect: About 90 percent of the time, this happens because your laptop’s Wi-Fi hardware is turned off.

Many laptops have an actual physical switch on the side that turns the wireless hardware on or off to save battery life. On some models it’s a touch-sensitive button near the keyboard that resembles an activity light but is also the control for powering up the various radios in your laptop. The least-obvious kind are “soft” switches–applications that you need to run to enable or disable the wireless radios.

If you can’t connect, the Windows network troubleshooter will typically launch; if it does, just follow the prompts. If the troubleshooter tells you that the laptop’s wireless hardware is turned off, you’ll have to figure out how to turn the radios back on. The method will vary from system to system. If the switch is a soft switch (a software utility), sometimes the Windows troubleshooter can turn the radios on for you. You’ll have to deal with a physical switch yourself, of course.

The other 10 percent of the time, you’re trying to connect over a wired network, but can’t. The cause: Lots of laptops disable wired networking to save juice if you haven’t plugged them into the wall. The solution here is to connect the power brick. If you can’t do that, you’ll need to enable wired networking manually in the Windows power management control panel, which you can find in the ‘System and Security’ control panel applet.
Sharing Files in Windows

All you want to do is share a few files between machines. Or maybe you want to copy files from one system to another. But you can’t seem to actually move files around the network, even if networking seems to be functioning properly. Here are a couple of fixes.

Password hell: So you bring up your spiffy new Windows 7 install. Everything seems to be working. Windows 7 sees the other systems in your network, and everything looks good. So you try to connect to another PC, and you get something like the screenshot to the right.

You could simply log in as the user on the target system, but that might not work–even if you know that login and password. You may have never created a password for the target system. If you need the security on your network, you’ll want to maintain the login authentication when connecting to other networked systems. If you’re using Windows Home Server, you’ll want to have a login for each user on the network.

If you’re not using WHS, or if you don’t need the security, you can always enable Windows Simple File Sharing. Bear in mind that you’re giving up considerable security if you do this, but if all your systems are behind a hardware firewall on a router, you should be okay.

To enable simple file sharing, first make sure that Windows File and Printer Sharing is enabled in the Local Area Connection Properties control panel.

Next, bring up the Windows ‘Network and Sharing Center’ (one of the Windows panels). Click the Change advanced sharing settings link in the left panel.

Once you get to the advanced-networking panel, make sure that several radio buttons are turned on. You’ll definitely want network discovery (so that you can see other systems) and file and printer sharing enabled. If you want simple file sharing, you should disable password-protected sharing by clicking the Turn off password protected sharing button.

Disabling login for Windows Home Server: Again, if you happen to be using Windows Home Server, you can’t really take advantage of simple file sharing. WHS requires user accounts, logins, and passwords. On the other hand, the annoyance of having to log in every time you connect–especially if you frequently access network shares–is bigger than you might think. You have an easy way around that, provided you know the login IDs and passwords for all the users on your network. This trick works with Windows XP, Windows Vista, and Windows 7.

First, bring up the Run box by clicking the Start menu button and typing Run. When you get the dialog box, type:

control userpasswords2

Note the specific syntax of the second word, with the number 2 attached at the end; this is important. You’ll see a dialog box that lets you enable or disable the requirement to log in when you boot up–or when you connect to a WHS share.

First, select the correct user account from the account list. Make sure that it’s highlighted. Then uncheck the box labeled Users must enter a user name and password to use this computer.

When you click Apply, another dialog box will pop up, and you’ll have to enter the user password twice. But once you’ve done that, you should never see a login screen again. When you boot up the PC, it will automatically boot into the account of the user whose name you specified. If that account name and password is the same one used on the Windows Home Server system, the user won’t have to log in to that as well.

Note that this trick also works if you want to access another Windows system that has user accounts with passwords. If all the systems in your network have the same login and password, you can bypass the login screen but still retain some semblance of security. I don’t actually recommend this approach, though: It’s better to have multiple accounts with different passwords, particularly if you’re using a normal Windows system as a de facto server. Just remember that you’ll be limited to ten maximum connections if you do this.

Source:http://www.pcworld.com/article/224311/windows_networking_troubleshooting_tips.html