有的网友反馈电脑能上QQ但不能上网，这到底是什么原因呢，下面笔者就为大家分析一下，大概包括以下几种原因：
一、感染了病毒所致
这种情况往往表现在打开IE时，在IE界面的左下框里提示：正在打开网页，但老半天没响应。在任务管理器里查看进程，（进入方法，把鼠标放在任务栏上，按右键—任务管理器—进程）看看CPU的占用率如何，如果是100%，可以肯定，是感染了病毒，这时你想运行其他程序简直就是受罪。这就要查查是哪个进程贪婪地占用了CPU资源。
找到后，最好把名称记录下来，然后点击结束，如果不能结束，则要启动到安全模式下把该东东删除，还要进入注册表里，（方法：开始—运行，输入regedit）在注册表对话框里，点编辑—查找，输入那个程序名，找到后，点鼠标右键删除，然后再进行几次的搜索，往往能彻底删除干净。
有很多的病毒，杀毒软件无能为力时，唯一的方法就是手动删除。
二、与设置代理服务器有关
有些筒子，出于某些方面考虑，在浏览器里设置了代理服务器（控制面板--Internet选项—连接—局域网设置—为LAN使用代理服务器），设置代理服务器是不影响QQ联网的，因为QQ用的是4000端口，而访问互联网使用的是80或8080端口。这就是很多的筒子们不明白为什么QQ能上，而网页不能打开的原因。而代理服务器一般不是很稳定，有时侯能上，有时候不能上。如果有这样设置的，请把代理取消就可以了。
三、DNS服务器解释出错
所谓DNS，即域名服务器（Domain Name Server）,它把域名转换成计算机能够识别的IP地址，如深圳之窗（
www.sz.net.cn）对应的IP地址是219.133.46.54，深圳热线（
www.szonline.net）对应的IP地址是202.96.154.6。如果DNS服务器出错，则无法进行域名解释，自然不能上网了。
如果是这种情况，有时候是网络服务接入商即ISP的问题，可打电话咨询ISP；有时候则是路由器或网卡的问题，无法与ISP的DNS服务连接。
这种情况的话，可把路由器关一会再开，或者重新设置路由器。或者是网卡无法自动搜寻到DNS的服务器地址，可以尝试用指定的DNS服务器地址。在网络的属性里进行，（控制面板—网络和拔号连接—本地连接—右键属性—TCP/IP协议—属性—使用下面的DNS服务器地址）。不同的ISP有不同的DNS地址，如电信常用的是202.96.134.133(主用) 202.96.128.68（备用）。
更新网卡的驱动程序或更换网卡也不失为一个思路。
四、系统文件丢失导致IE不能正常启动
这种现象颇为常见，由于：
1、系统的不稳定 表现为死机频繁、经常莫名重启、非法关机造成系统文件丢失；
2、软硬件的冲突 常表现为安装了某些程序引起网卡驱动的冲突或与IE的冲突。自从INTEL推出超线程CPU后，有一个突出的问题是XP SP1下的IE6与超线程产生冲突；
3、病毒的侵扰 导致系统文件损坏或丢失。
如果是第一种情况，可尝试修复系统，2K或XP系统下，放入原安装光盘（注意：一定要原安装光盘），在开始—运行里输入sfc /scanow，按回车。98的系统也可以用sfc命令进行检查。
如果是第二种情况，可以把最近安装的硬件或程序卸载，2K或XP的系统可以在机器启动后，长按F8，进入启动菜单，选择“最后一次正确的配置”，若是XP系统，还可以利用系统的还原功能，一般能很快解决问题。
如果是XP的系统因超线程CPU的原因，可以在BIOS里禁用超线程，或升级到SP2。（当然，XP如何升级SP2涉及到很多知识及要注意的问题，在此限于篇幅不再详述）。这种情况下，QQ里自带的TT浏览器一般能正常浏览，可改用一试。
如果是第三种情况，则要对系统盘进行全面的查杀病毒。
还有一种现象也需特别留意：就是能打开网站的首页，但不能打开二级链接，如果是这样，处理的方法是重新注册如下的DLL文件：
在开始—运行里输入：
regsvr32 Shdocvw.dll
regsvr32 Shell32.dll（注意这个命令，先不用输）
regsvr32 Oleaut32.dll
regsvr32 Actxprxy.dll
regsvr32 Mshtml.dll
regsvr32 Urlmon.dll
regsvr32 Msjava.dll
regsvr32 Browseui.dll
注意：每输入一条，按回车。第二个命令可以先不用输，输完这些命令后重新启动windows，如果发现无效，再重新输入一遍，这次输入第二个命令。还有，如果是98的系统，到微软的网站上下载这个文件也许更简单，这个文件的下载地址是：
http://download.microsoft.com/download/msn...us/mcrepair.exe
五、IE损坏
以上方法若果都不奏效，有可能是IE的内核损坏，虽经系统修复，亦无法弥补，那么重装IE就是最好的方法了。
如果是98或2K系统，IE的版本若是5.0，建议升级到6.0。
98的系统如果已经升级安装了6.0，那么在控制面板里点击添加/删除程序，将会弹出一个修复对话框，选择默认的修复，重新启动即可。
如果是2K+IE6.0或XP（自带的IE就是6.0的）的系统，重新IE有点麻烦，有两种方法：
1、打开注册表，展开HKEY_LOCAL_MACHINESOFTWAREMicrosoftActive SetupInstalled Components{ 89820200-ECBD-11cf-8B85-00AA005B4383 }，将IsInstalled的DWORD的值改为0即可；
2、放入XP安装光盘，在开始—运行里输入“rundll32.exe setupapi,InstallHinfSection DefaultInstall 132%windir%Infie.inf”
注：重装IE并不一定就能解决问题，仅是一个处理问题的思路而已。
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.
