China DOS Union

Internal company LAN. A newly installed system and a new computer. Suddenly cannot access the Internet, cannot access internal company network or external network, but can use QQ.

Found: When entering a URL such as input www.163.com, in the taskbar below, the system will automatically add www.www.163.com.com or www.www.163.com.net. as shown in Figure A. After a while, an error message will be displayed: "Internet Explorer cannot open the search page. As shown in Figure B".

Enter CMD, can PING any external or internal IP, all show normal. Check the port, not sure if it is normal, as shown in Figure C.

The company uses DHCP to automatically assign IP, uses fiber optics, and moving this machine to another office also doesn't work. Please give advice! IE options have been checked and are normal

This kind of problem has no other way but to search on the Internet by yourself and slowly rule out possibilities one by one

Yeah, so I came here to post.

Some netizens report that the computer can log in to QQ but cannot access the Internet. Here's what the author analyzes for everyone, roughly including the following reasons:

### 1. Caused by virus infection
This situation is often manifested as when opening IE, in the lower left box of the IE interface, it prompts: "Opening the web page", but it doesn't respond for a long time. Check the process in the Task Manager (the method is: place the mouse on the taskbar, right-click - Task Manager - Processes), and see how the CPU usage rate is. If it is 100%, it can be confirmed that it is infected with a virus. At this time, it is simply a torment to run other programs. Then you need to find out which process is greedily occupying CPU resources.
After finding it, it is best to record the name, and then click to end. If it cannot be ended, you need to boot into safe mode to delete this thing, and also enter the registry (method: Start - Run, enter regedit). In the registry dialog box, click Edit - Find, enter that program name, find it, right-click and delete it, and then perform several more searches, which can often completely delete it.
There are many viruses. When the anti-virus software is powerless, the only way is to delete it manually.

### 2. Related to setting up a proxy server
Some people, for certain considerations, set up a proxy server in the browser (Control Panel - Internet Options - Connections - LAN Settings - Use a proxy server for LAN). Setting up a proxy server does not affect QQ connecting to the Internet because QQ uses port 4000, while accessing the Internet uses port 80 or 8080. This is the reason why many people don't understand why QQ can be used but the web page cannot be opened. And the proxy server is generally not very stable, sometimes it can be used, sometimes it cannot. If there is such a setting, cancel the proxy.

### 3. DNS server interpretation error
The so-called DNS, that is, Domain Name Server, it converts the domain name into an IP address that the computer can recognize. For example, the IP address corresponding to Shenzhen Window (www.sz.net.cn) is 219.133.46.54, and the IP address corresponding to Shenzhen Hotline (www.szonline.net) is 202.96.154.6. If the DNS server has an error, the domain name cannot be interpreted, and naturally cannot access the Internet.
If this is the case, sometimes it is the problem of the network service access provider, that is, ISP. You can call to consult ISP; sometimes it is the problem of the router or the network card, unable to connect with the ISP's DNS service.
In this case, you can turn off the router for a while and then turn it on again, or reset the router. Or the network card cannot automatically search for the DNS server address, you can try to use the specified DNS server address. Do it in the network properties (Control Panel - Network and Dial-up Connections - Local Connection - Right-click Properties - TCP/IP Protocol - Properties - Use the following DNS server addresses). Different ISPs have different DNS addresses. For example, the common ones for telecom are 202.96.134.133 (primary) and 202.96.128.68 (secondary).
Updating the driver of the network card or replacing the network card is also a way to think about.

### 4. System files are lost and cause IE to not start normally
This phenomenon is quite common, due to:
1. System instability, manifested as frequent system freezes, frequent inexplicable reboots, and system file loss caused by illegal shutdowns;
2. Hardware-software conflicts, often manifested as installing some programs causing conflicts with the network card driver or with IE. Since INTEL launched hyper-threaded CPUs, there is a prominent problem that IE6 under XP SP1 has conflicts with hyper-threading;
3. Virus intrusion, causing system file damage or loss.
If it is the first case, you can try to repair the system. In 2K or XP systems, put in the original installation CD (note: it must be the original installation CD), and enter sfc /scanow in Start - Run, then press Enter. The 98 system can also use the sfc command to check.
If it is the second case, you can uninstall the recently installed hardware or program. In 2K or XP systems, you can start the machine and then press the F8 key for a long time, enter the boot menu, select "Last Known Good Configuration". If it is an XP system, you can also use the system restore function, which can generally solve the problem quickly.
If it is an XP system due to the hyper-threaded CPU, you can disable hyper-threading in the BIOS or upgrade to SP2. (Of course, how to upgrade XP to SP2 involves a lot of knowledge and points to note, which will not be detailed here due to space limitations). In this case, the TT browser built into QQ can generally browse normally, and you can try to use it instead.
If it is the third case, you need to thoroughly scan and kill viruses on the system disk.
There is also a phenomenon that needs special attention: that is, you can open the homepage of the website, but cannot open the secondary links. If this is the case, the processing method is to re-register the following DLL files:
Enter in Start - Run:
regsvr32 Shdocvw.dll
regsvr32 Shell32.dll (Note: Do not enter this command first)
regsvr32 Oleaut32.dll
regsvr32 Actxprxy.dll
regsvr32 Mshtml.dll
regsvr32 Urlmon.dll
regsvr32 Msjava.dll
regsvr32 Browseui.dll
Note: Press Enter after each input. The second command can not be entered first. After entering these commands, restart Windows. If it is found to be invalid, enter it again, and this time enter the second command. Also, if it is a 98 system, it may be simpler to download this file from the Microsoft website. The download address of this file is:
http://download.microsoft.com/download/msn...us/mcrepair.exe

### 5. IE is damaged
If the above methods are not effective, it is possible that the kernel of IE is damaged. Although the system is repaired, it cannot be compensated. Then reinstalling IE is the best method.
If it is a 98 or 2K system, and the version of IE is 5.0, it is recommended to upgrade to 6.0.
If the 98 system has been upgraded and installed with 6.0, then click Add/Remove Programs in the Control Panel, and a repair dialog box will pop up. Select the default repair and restart.
If it is a 2K + IE6.0 or XP (the built-in IE is 6.0) system, reinstalling IE is a bit troublesome. There are two methods:
1. Open the registry, expand HKEY_LOCAL_MACHINESOFTWAREMicrosoftActive SetupInstalled Components{ 89820200-ECBD-11cf-8B85-00AA005B4383 }, and change the value of IsInstalled DWORD to 0;
2. Put in the XP installation CD, and enter "rundll32.exe setupapi,InstallHinfSection DefaultInstall 132%windir%Infie.inf" in Start - Run.
Note: Reinstalling IE does not necessarily solve the problem, it is just a way to handle the problem.

I used to encounter the opposite problem: I could access the internet, but I couldn't log in to QQ.

I have also encountered this problem. For reference:lol:

The analysis on the 4th floor is very wonderful. The viruses nowadays are indeed very powerful. As soon as you open IE, the virus runs, it's simply like a lingering ghost.

ON GOOGLE!
From my practice, the most likely issues are "infected with a virus" and "DNS settings".


As for "can access the internet but cannot access QQ"
The recent issues of CFAN have all introduced that it is either that someone has manually modified several files in the QQ folder or the network administrator has blocked the ports used by QQ, etc.!