It may not be due to multifaceted reasons. It may have a relationship with computer hardware systems, operating systems, and network health. If the user does not encounter a problem, you can check the following steps:
1, motherboard
Fault phenomenon: Compatibility issues, NIC and the PCI slot of the motherboard contact. No network card is detected.
Recommendation: Change the motherboard and change the PCI tank try.
2, NIC
Fault Phenomenon: Use Right-click on the "My Computer" icon on the desktop, click "Properties", "Device Manager", "Network Adapter", and check if the network card is normal. If a yellow exclamation point is displayed on the NIC option, the problem of the network card's driver is issued.
Recommendation: Install the correct network card driver. There is a conflict in the IRQ value and the I / O address (in the installation of multi-NICs, in order to avoid conflicts, we all drop COM1 or COM2 Disable).
3, wireless network card
Fault Phenomenon: Unable to get IP addresses, wireless network cards do not communicate with the wireless router, indicating that the indicator of the NIC flashes, unstable.
Recommendation: You need to determine the drive installation of the wireless network card, then make sure that the ESSID setting in the wireless network card is the same, if everything is correct, the indicator should be a normal bright. If the ESSID is correct, it is still not possible to get the IP address, you need to check if the WEP (encrypted) setting of the wireless network card is turned on, the default is closed, if the network card is turned on, turn it off.
4, network protocol
Fault Phenomenon: Click "Start", "Run", enter the ipconfig command in the command line. Check if IP configuration information is consistent.
Recommendation: Set the correct network card attribute or parameter, such as 10M half-duplex or 100M full duplex; and the correct network configuration, such as IP, subnet mask, gateway, DNS or DHCP, etc.
5, troubleshoot
Fault Phenomenon: There is no way to connect, because the ARP cache or switch MAC address table cache is not emptied, and network paralysis caused by the broadcast storm.
Suggest: Unplug the network cable, shut down, wait a few minutes to restart.
6, operating system
Fault Phenomenon: Since the user's use is slow, the system software is often wrong, even by viral infection, data is damaged. These have seriously affected the Internet speed of users who use this uncomfortable operating system, serious or even unable to access the Internet, and the system crashes.
Recommendation: anti-virus, restore system files; reload the operating system.
7, browser settings errors
Fault Phenomenon: Bless the "Connection" option of IE, you cannot normally browse the web.
Recommendation: Set the Internet type correctly. If it is online through a proxy service, please fill in the IP address and port number of the proxy server correctly; if not, please do not check the "By Proxy" option.
8, DNS server
Fault phenomenon: Tip DNS error when browsing the web with IE
Recommendation: ISP provider's DNS server error, does not correctly perform conversion between domain name → IP address, this time you can use the IP address of the website in the browser address bar to browse the web.
9, network cable
Fault Phenomenon: Click "Start", "Run", enter ping 192.168.0.1 -t (192.168.0.1 representative gateway) in the command line, indicating that the feedback information is a network line problem.
Suggest: check if the sort of the network cable is correct, is it connected to the network card after the computer, determine that the network cable has been connected, and then check the link light on the NIC is not bright (in the network card access network). If it is not bright, it means that the network link to the switch is not normal. 10, network equipment
Fault Phenomenon: Click "Start", "Run", enter ping 192.168.0.1 -t (192.168.0.1 representative gateway) in the command line, if the feedback information is the request timed out, indicating that the network device is not working properly.
Recommendation: Check the port, indicators, and configurations of the HUB, switches, routers. For example, the level of the HUB cannot be shared with the first port.
11, connectivity of the external network
Fault Phenomenon: Click "Start", "Run", enter ping www.google.com -t in the command line, if the feedback information is the request timed out, indicating that the NIC or network is not normal. If the feedback information is Destination Host Unreachable, it indicates that the network cable is not connected to the NIC. If the feedback information is similar to the reply from 218.104.224.106: BYTES = 32 Time = 40ms TTL = 239, indicating that the connection to this IP address is normal.
Recommendation: Ask ISP.
12, website
Fault phenomenon: Some websites or web pages can't open.
Recommendation: First confirm that all websites are not going to still be a separate website or web page can't open? It may be that no choice of cookie or Java in the browser settings, or it may be that individual websites are too busy without receiving more users.
13. Theoretically solve the problem in theory, summarizing the following:
(1) Identify the fault phenomenon and predict the location of the fault cause.
(2) Describe the failure phenomenon and determine the fault range.
(3) Test, reduce the fault range.
(4) Find faults and quarantine or exclude faults.
