I couldn't begin to cover every possibility for a network connection failure or even write a manual that would work for every network arrangement. However, here are a few tips for diagnosing a failing or ailing connection. This tutorial assumes that you are making a TCP/IP connection. You should check for improvements between each step.
- Ensure that any firewalls are configured properly to allow access if present.
- Run a full Antivirus scan and Adaware/Spyware scan.
- Check the physical connection.
- For a "wired" connection, begin by checking that the network cable is plugged into the network adapter and to the wall jack (or router/switch/etc.) Be sure that connections aren't too loose and that the cable is in good physical condition (no kinks, cuts, or breaks). If possible, properly test the cable for pin-out and signal strength. If you do not have access to the proper test equipment, swap the cable out for one that is known to work.
- For a wireless connection, be sure that your hardware is supported by the local network. Also be sure there is a network available and that you have the proper credentials.
- Confirm your Local Area Connection settings are configured properly for the connection. Be sure that you are using the proper Authentication method if required. Additionally,
- For connections using DHCP, use your Local Area Connection's repair feature. This will attempt to release and renew your IP lease.
- For connections without DHCP, be sure that you are set to use your assigned IP address, Subnet Mask, and Default Gateway along with any other NetBios, WINS, or DNS settings.
- Attempt to repair/reinstall TCP/IP and Winsock settings. This can be done manually or with a utility like WinsockXP Fix.
- Install the latest drivers for your network adapter and check for any hardware conflicts.
- Check the activity lights on your network adapter as well as any routers, switches, or gateways. Try removing power from any such devices and allowing them to cycle back up.
- Remove any such devices and connect your machine directly to your modem. If this solves the problem, replace the removed device with a new one.
- Replace your network adapter (swap with another working one if possible first)
- Replace your Cable or DSL modem.