Wired and Wireless NICs suddenly cannot connect to Internet

One day I came home and my family PC could not load anything in the browser. The network icon in the system tray shows connected but the yellow-triangle exclamation point is present.


Starting in Safe Mode w/Networking does allow Internet browsing to work. This is used by my kids; I think my son tried to install something that is interfering. Between the dashed lines are the troubleshooting steps I performed/confirmed.

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There are no proxy servers set up in the browser configs. I have IE, Firefox, and Chrome; none of them work.

This problem affects the wired and wireless NICs. They will both get a DHCP address from the router but then they will not pass any data. They cannot ping the router.

McAfee Security Center is installed and working properly. I disabled the firewall and that did not help.

The ARP table on the PC looks good and has an entry for everything else on the network including the router. I checked the router and the MAC address of the LAN port matches the one in the PC's ARP table.

Two PS3's, an iPads, two iPhones, and an HP printer all work on the same wireless network without issue. My work laptop is working fine on the wireless and it works fine using the same router port and cable that will not work for the home PC.

All network related services are started on the PC.
Anti-Virus was up to date to the day networking stopped and a full scan revealed no infections at all.

DNS entries are present. The PC will get DHCP but then cannot communicate or ping anything else in the network. It's almost like broadcast will work but not unicast.

Device manage sees both NICs and their drivers. I deleted the NICs and rebooted allowing Windows to rediscover them. The problem came right back.

There are no proxy servers set up in the browser and I have IE, Firefox, and Chrome. None of them work.

It seems to be O/S related since it impacts only this machine, affects both NICs, and won't even respond to pings.
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It looks like System Restore was ever enabled so I may not have any restore points to fall back on.


Anyone have any ideas for next steps besides re-installing the operating system.

Thanks.

What DHCP address are they recieving from the router, and what brand router do you have?

Motorola SURFboard SBG6580. The wired and wireless NICs receive a DHCP address from the subnet configured on the router: 192.168.69.17

The standard IP for the Motorola should be 192.168.100.x ; did you change the third digit to 69 yourself?

chuckbr said:

One day I came home and my family PC could not load anything in the browser. The network icon in the system tray shows connected but the yellow-triangle exclamation point is present.


Starting in Safe Mode w/Networking does allow Internet browsing to work. This is used by my kids; I think my son tried to install something that is interfering. Between the dashed lines are the troubleshooting steps I performed/confirmed.

------------------------------------------
There are no proxy servers set up in the browser configs. I have IE, Firefox, and Chrome; none of them work.

This problem affects the wired and wireless NICs. They will both get a DHCP address from the router but then they will not pass any data. They cannot ping the router.

McAfee Security Center is installed and working properly. I disabled the firewall and that did not help.

The ARP table on the PC looks good and has an entry for everything else on the network including the router. I checked the router and the MAC address of the LAN port matches the one in the PC's ARP table.

Two PS3's, an iPads, two iPhones, and an HP printer all work on the same wireless network without issue. My work laptop is working fine on the wireless and it works fine using the same router port and cable that will not work for the home PC.

All network related services are started on the PC.
Anti-Virus was up to date to the day networking stopped and a full scan revealed no infections at all.

DNS entries are present. The PC will get DHCP but then cannot communicate or ping anything else in the network. It's almost like broadcast will work but not unicast.

Device manage sees both NICs and their drivers. I deleted the NICs and rebooted allowing Windows to rediscover them. The problem came right back.

There are no proxy servers set up in the browser and I have IE, Firefox, and Chrome. None of them work.

It seems to be O/S related since it impacts only this machine, affects both NICs, and won't even respond to pings.
--------------------------------------------------------

It looks like System Restore was ever enabled so I may not have any restore points to fall back on.


Anyone have any ideas for next steps besides re-installing the operating system.

Thanks.

Maybe you need to read about the McAfee update problem which has been causing connection problems. I believe this is the source of your problems.

McAfee - Resolving the recent update issues with McAfee Consumer Products

I did change the 3rd octet. Did it a long time ago with a different router and always kept it that way because I didn't feel like re-IPing some statics. The McAfee update is very interesting though. I am checking that out right now. Thanks!

It was McAfee. I ran the removal tool and rebooted. Everything is back to normal. It must have had some corrupt update. Thanks everyone!!

Yep no problem chuckbr, glad I could help. :)