January 03, 2012, 3:02 PM — Setting up and maintaining your home PC network is easier than ever before in Windows 7--but that's not saying much. Many networking issues still aren't easily addressed from Windows 7's control panels. That's why we've compiled a list of common networking problems and quick fixes.
Reset Your IP Address
If your system's connection to a network is unreliable, or you're getting IP address conflict error messages, try renewing your IP address. First, click on the Start button, navigate to the Command Prompt (Start Menu, Applications, Accessories, Command Prompt), right-click it, and select Run as Administrator from the menu.
This will open a Command Prompt window with Administrator privileges. At the C:\Windows\system32\ prompt, type ipconfig /release and press Enter to release your current IP address (you'll lose your connection to the network at this point). Then type ipconfig /renew and press Enter. You'll see your new network connection information scroll by in the Command Prompt. Type exit at the prompt and press Enter to close the command prompt window.
Flush Your DNS Cache
Whenever you type a URL into a Web browser, your PC asks your Domain Name Service server (DNS server) to translate that into an IP address, and caches that information. However, that cache can become outdated or corrupt, which can cause Internet connection problems. To clear your DNS cache, navigate to and open the Command Prompt with Run as Administrator, type ipconfig /flushdns, and press Enter.
Restarting a Windows 7 system will also flush its DNS cache, but if any applications (malware, perhaps) are altering the cache, flushing manually could help.
Power Cycle Your Modem/Router the Right Way
Your broadband modem's connection to the Internet will occasionally become unreliable, and restarting it can fix that. Same goes for the connection between a router and a broadband modem as well.
To reset your broadband modem and router, disconnect their power cables, and leave the modem and router off for 30 seconds or so. Next, connect the modem's power cable to restore its power first. Wait a few moments for the modem to renegotiate its connection to the Web and establish a link, and then restore power to the router.
Disable and Add Exclusions to Windows Firewall
Windows 7's built-in firewall constantly asks you to allow or deny an application's network traffic. If you've mistakenly blocked an application and want to unblock it (or the other way around), you'll have to manually change some settings in the Windows Firewall control panel.