Most of the time, Internet connectivity issues affect multiple devices on a network, but there are occasions where only one PC will experience these problems. Typically this is caused by problems with the PC itself, whether it be a connection setting, malware infection, or a software conflict.
If you use a wireless connection to access the Internet, wireless signal strength plays a significant role in trouble-free use. Wi-Fi devices need to be within 150 feet of an access point when indoors and within 300 feet outdoors. Wi-Fi range is significantly reduced by obstructions between the device and interference in the area. The transmission qualities of the access point itself can also reduce range; weaker transmitters mean reduced range. Try moving closer to an access point to resolve signal strength issues.
Certain types of malware disrupt or disable your Internet connection. Ensure that your computer is running anti-virus software and run a scan of your computer for any viruses. Additional steps may be required to repair any damage as a result of a malware infection. This may include repairing any file associations (how the operating system opens files), or running a removal tool to uninstall any rogue applications. Security firm ESET provides instructions on what you need to do if your PC is infected by malware (link in Resources).
Incorrect connection settings can disrupt your Internet access. Try running the Network troubleshooter within Windows, or make sure your connection settings are correct in the Network panel within System Preferences in Mac OS X. Confirm your settings with technical support representatives from your Internet service provider to ensure they are correct. Another potential issue is use of a proxy. When a proxy fails, it can appear as if there is an Internet connection issue. Disable the proxy and attempt to connect again.
A less common issue is related to software-based malware protection called a firewall. Firewalls are intended to block potentially malicious connections to and from your computer, but from time to time can mistakenly block legitimate traffic. Ensure that your Web browser is listed as an application authorized to pass traffic through the firewall. Also ensure that you aren’t running two firewalls at once: both Windows and Mac OS X include built-in firewall protection, but some anti-virus software also includes the same feature. Running both at the same time can cause conflicts, which may end up blocking legitimate traffic.
- UNC: What Is the Range of a Typical Wi-Fi Access Point?
- ESET: No Internet Connection Due to Malware
- Microsoft: Wired and Wireless Network Problems
- Apple: Mac OS X - Troubleshooting a Cable Modem, DSL, or LAN Internet Connection
- Microsoft: What Is a Firewall?
- Netgear: Disabling Conflicting Firewalls Such as Windows XP, McAfee, Norton, or Zone Alarm
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