Q – My Windows 8.1 machine can’t get on the Internet. I have McAfee antivirus so the machine is safe. It flashes back a message to reinstall Windows which I would rather not do. What’s wrong?
A – Naturally this generated a lot of discussion. First a member asked if other computers in the house have Internet access and they do. Next someone asked if the problem machine can send and receive email and the answer was yes. So we know that the router and its connection to the Internet are working, and we know that the problem machine actually can access the Internet. Since the machine can send and receive email, all the network software is working – the network adapter, DNS, etc. Now the problem is narrowed down the browser which “opens to an empty white window and nothing is ever displayed.” This is a symptom of a browser hijacker but the questioner says he is using Google Chrome. Both Chrome and Internet Explorer (IE) have an option to return all settings to “factory specs”. For IE this is found in the Internet Options applet in Control Panel. On the Advanced tab near the bottom is “Reset Internet Explorer settings”. Click the ‘Reset…’ button and follow instructions. For Chrome, the ‘Reset Browser Settings’ button is found at the very bottom of the advanced settings portion of the Settings dialog. To get there, click the Options icon (a stack of 3 horizontal lines) at the top right on the Chrome window. [Note: the preceding is a distilled version of the actual discussion.]
D – As the discussion ended, there were two good suggestions: The first was to scan the computer with the new version 2.0 of Malwarebytes. There is still a free version. The second suggestion was to take your machine to the Microsoft Store in the Danbury Mall. The Answer Desk will tune up your Windows 7 or 8 machine for ½ hour for free. It’s best to make an appointment in advance.
Q – What is a “zero day” vulnerability?
A – From WikiPedia: “A zero-day (or zero-hour or day zero) attack or threat is an attack that exploits a previously unknown vulnerability in a computer application, one that developers have not had time to address and patch. It is called a “zero day” because the programmer has had zero days to fix the flaw (in other words, a patch is not available). Once a patch is available, it is no longer a “zero day exploit”. It is common for individuals or companies who discover zero-day attacks to sell them to government agencies for use in cyberwarfare.” The complete article is at wikipedia.org/wiki/Zero-day_attack. My answer at the meeting said essentially the same thing, but this is better. Read the complete article for a more complete understanding.
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How to list your machine’s TCP/IP configuration – the IPCONFIG command
We mentioned using the IPconfig command several times during the discussion. The IPconfig command can list all of the TCP/IP networking configuration information in effect when it is run. In addition, it is most commonly used to release and renew a dynamic IP address.
Like all command line tools, it must be run in a Command Prompt window, not “Run”. To open a command window in Vista or Win7, type “cmd” into the Start Menu search box and hit enter. In Win8, type “cmd” into the Start Screen and hit enter. When the window opens, you will see the command prompt in the window. Now type “ipconfig” to run the command. The results may scroll up out of the window, but the text can be scrolled back as needed for review.
To see all the usage options, type “ipconfig /?”. Abbreviated usage help is shown below:
USAGE:
ipconfig [/allcompartments] [/? | /all |
/renew [adapter] | /release [adapter] |
…many lines not shown…
Options:
/? Display this help message
/all Display full configuration information.
/release Release the IPv4 address for the specified adapter.
/renew Renew the IPv4 address for the specified adapter.
The options beyond our scope are not shown.
The “/all” option does exactly what it implies and displays a long list of information for all the network adapters in the computer. There are more “adapters” in a modern computer than you might think. The key information to look for is the IPv4 address in the form: 192.168.1.5. This is normally supplied by your router’s DHCP server. If you see “Media disconnected” instead of an IP address, then the Ethernet cable is not connected or your Wi-Fi is not “connected”. If Windows is reporting “limited” connectivity and the IP address starts with “169”, then your router is not supplying IP addresses and your adapter has “auto configured”. Check other computers on the same network to help diagnose this problem before attacking your router.
Next look for the DNS server address(es). If the DNS is blank, your computer cannot resolve a domain name like DACS.ORG into its IP address (69.89.31.186). This makes it appear that you have no Internet access. Again, DNS information is normally supplied by your router. If other computers on the same network are working, then look at the cable or Wi-Fi configuration.
Sometimes IP problems can be cleared by releasing and renewing the IP address. The command “ipconfig /release” will clear the current address and “ipconfig /renew” will get a new IP address from the DHCP server, assuming that it is working. Try this before attacking your router.