Lost Internet Connection on Upstairs Computer . . .

Mike Brinkmeyer · From: Houston, Texas

Our computer upstairs has suddenly lost its high speed internet connection which feeds off the downstairs computer via a modem and Linksys router (hardwired, not wireless). The internet connection icon in the system tray says " Exclamation

Status: Limited or No Connectivity". I suppose I've lost a setting for some reason but I'm totally illiterate when it comes to IP address settings, networking, etc. Oh Well

Can someone please help in getting the internet connection restored on this computer? Thanks, Mike

Andy Sandoval · From: Bakersfield, California, USA

Try right clicking on the little computer icon near the clock (lower right hand corner of screen)on the computer that's not connecting to the Internet and choose "repair", sometimes that will reset things. You can also unplug the power chord from the back of the router and then plug it back in to reboot the router. Good luck.

Mike Brinkmeyer · From: Houston, Texas

Thanks Andy - I gave that a try and unfortunately still no connection . . .

Jack Stoner · From: Kansas City, MO

The first thing to do is restart the PC and see if it connects. If not, reseat the Ethernet cable on both ends - at the PC and at the Router. You may have to restart the PC again after the cable reseat.

If it's still no go, try a different port on the router and restart the PC after changing the port. If it still does not work, connect the "upstairs" PC directly to the modem (disconnect the router and connect the PC to the modem). If you do this you MAY have to repower the modem and wait until it "trains" (syncs back up) and then restart the PC again. If it works connecting directly to the modem it isolates the problem to the Router. I recently had to replace my wired Linksys router because of a port p;roblem that I coiuldn't clear.

Some routers have a "supervisory" or "Administrative" function that you can go into the router and check the status. I can't tell you how to get into yours, you'll have to check the manual for the router.

Earnest Bovine · From: Los Angeles CA USA

Have you already tried
- swap Ethernet cables to make sure you have a good one
- restarting the problem PC,
- restarting the router (a hard restart probably involves pressing a pin into a recessed switch on the back of the router for a few seconds).
- connect the PC that works to the upstairs end of the Ethernet cable (does that work?)
- connect the PC that doesn't work to the downstairs Ethernet cable (does that work?)

You can communicate with many routers by typing http://192.168.2.1/ or just 192.168.2.1 into your browser's address line. What happens when you do that?

Mike Brinkmeyer · From: Houston, Texas

Thanks guys for the responses. I connected the disabled computer upstairs directly to the modem downstairs using cables that I knew were good and still no connection. So, I'm thinking that some network setting maybe disabled on the upstairs computer. I'd like to rule out that possiblity before I swap both both computers to see if the results will change or stay the same. Is there a network setting on the computer that will get it to correspond with the modem downstairs? BTW, both PC's are XP os.

Wiz Feinberg · From: Mid-Michigan, USA

Mike;
First of all, a good network connection will usually show up in your System Tray, as a little computer-to-computer icon. Do you see the network connection icon in the Systray? Is it green, or does it have a red X in it? If it has an X you have no connectivity. If the network cable is fully seated at both ends and you can't get the network adapter to recognize the modem/router at the other end, something has become disabled on your faulty computer. Let's explore what can cause this problem.

The network adapter driver is corrupted
The adapter is fried or loose in it's socket
You have a LSP infector that has been partially uninstalled, but the TCP stack has not been rebuilt
System files are corrupted
The DCHP Client Service has Stopped
You have crosslinked sectors due to a bad shutdown
The network connection needs to be flushed and reset.
The network settings were modified by somebody, or some program and do not match your router's settings.
The network chipset has been disabled in the BIOS.

Solutions

1: reinstall the driver from the disk that came with the computer, or the driver files stored on the computer. Sometimes uninstalling the device and rebooting will cause Windows to "find it" again and reinstall the driver, fixing the glitch.

2: Open the right side of the computer case and look for the network adapter. If it is a separate plug-in card it will be in a socket, at the rear. Check the card to make sure it has a screw securing it to the back panel and that it has not shifted loose in the socket. If it is a chip built into the motherboard, there is nothing you can check physically.

3: Run a check for spyware and backdoors. Use Spybot Search and Destroy if you have it, or another up to date anti spyware program. It is possible to rebuild the TCP stack from the command line, replacing any hostile stacks in the process with the original Windows stack. Open a CMD window and type this command:
netsh winsock reset catalog

4: Run a System File Check and replace corrupted files. Insert your Windows XP CD into the CD player, then exit the splash screen, the goto Start > Run and type in:
SFC /SCANNOW and press ENTER.

5: Verify that the DHCP Client and DNS Client Services are running and set to Automatic. Go to Start > Run and type in: SERVICES.MSC and press Enter. When the Services management console opens scroll down to the letter D and find DHCP Client and then DNS Client. They should say Started and Automatic. If they are stopped (not started) double click on the services to open them, then click on START to start them. If the Startup Type is not Automatic, make it so from the flyout options. Click Apply and exit. If the Services will not start you have corrupt system files.

6: Go to My Computer and right-click on the icon for your C (boot) drive and select Properties. On the Properties box, click on the TOOLS tab. On the Tools page, in the Error Checking section, click on the "Check Now" button. A box will appear with two checkboxes. Check the top option to find and fix file system errors, and click Apply. When you close the options box another alert will popup, telling you that Windows cannot perform a disk check at this time asking if you wish to schedule it to run on the next reboot. Tell it YES. Close all applications and reboot. Chkdsk will run during the reboot cycle and fix minor file system errors, like crosslinked files.

7: To flush and reset the network connections open a DOS Window by going to Start > Run and typing in: CMD and pressing Enter. When the DOS window opens type the following commands, pressing Enter after each one. You'll have to wait on some of them to complete before entering the next command.

IPCONFIG /FLUSHDNS
IPCONFIG /RELEASE
IPCONFIG /RENEW
IPCONFIG /ALL

If this fixes the problem you will see an IP address that is assigned by your router, listing the router's IP as the Gateway. You are probably connected to the net at this time. If the IP address begins with 169. you are only connected to the loopback adapter and are not receiving an IP from your router.

8: You can check the integrity of the network connection by going the icon in your Systray and right clicking on it, then choosing Properties. When the Net work Connection Properties opens look for TCP/IP and double click on it. When TCP/IP Properties opens look at the General tab and make sure there are no numeric entries in any field, unless you knowing placed them in those fields. Set everything to Automatically Obtain an Address and apply the changes, then reboot.

9: If the BIOS has been messed with the on-board network adapter may have been disabled. Reboot the computer and begin tapping the Delete key, or F1, or whatever your computer starting screen tells you to press to enter "Setup." Look through the various tabs until you find the one that lists on-board peripherals. Find the network adapter and see if it is disabled. If so, enable it, using the arrow keys and Enter key, or whatever key is required to change an option. Save the change and exit to reboot.

Hopefully, something here will help. If not, your network adapter may be dead and in need of a replacement network card. You can buy them at office supply and computer stores for about $15 to $20 dollars.
_________________
"Wiz" Feinberg, Moderator SGF Computers Forum
Security Consultant
Twitter: @Wizcrafts
Main web pages: Wiztunes Steel Guitar website | Wiz's Security Blog | My Webmaster Services | Wiz's Security Blog

Mike Brinkmeyer · From: Houston, Texas

Wiz - thanks a bunch for the thorough troubleshooting list. I've started first with the items that don't relate to hardware. When I did the IPCONFIG/RENEW in the DOS Window, I got a message that said "An error occured while renewing interface local area connection. The requested service provider could not be loaded or initialized". And yes, the IP address in the IPCONFIG/ALL command does begin with 169. Does this help in closing in on my problem? Thanks again . . .

Wiz Feinberg · From: Mid-Michigan, USA

Mike Brinkmeyer · From: Houston, Texas

Thanks once again Wiz - I will address those items when I get home this evening and see what happens. One sidenote though - I was reading in another topic a post that you made in regards to the hazards of installing and using the new free version of AVG 8.0. I'm relatively certain that is what is installed on my ill computer (I'll confirm that when I get home). Do you think that could possibly be the root of my failed network connection?? If so, what would you recommend at this point??

Wiz Feinberg · From: Mid-Michigan, USA

Mike Brinkmeyer · From: Houston, Texas

Success!! Rebuilding the Winsock did the trick. What a relief Very Happy

. Thanks Wiz for your comprehensive directions in getting me through this - in lingo that even I could understand. Thanks also to Andy, Jack and Earnest for their input. What a great forum this is!

Wiz Feinberg · From: Mid-Michigan, USA

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