Tech support help needed: "Ethernet doesn't have a valid IP configuration"

[Frankster]

Greetings, up to now this forum has a good track record of solving my tech problems, am hoping this trend continues.

Internet setup: My home has a wireless router in the front room, my desktop (win8) is connected to my laptop (win7) through a USB cable and has access to the internet through it. Not an ideal setup I know, but I can't do anything else at this time.

The problem: Since 2 days ago my desktop has had "no internet access" and yellow warning triangle appears on the net icon. There is no apparent reason why it stopped working that I can tell, this has happened in the past for small amounts of time but restarting the computers or the router had always fixed it, just not this time. My laptop and other home devices can still access the net just fine so problem is just with the desktop.

When trying to run windows network diagnostics,it tries to "reset ethernet adapter" and then it tells me "ethernet doesn't have a valid IP configuration" and can't fix it.

IPconfig:
Ethernet adapter Ethernet:
Connection-specific DN S suffix:
Link-local IPv6 Address: fe80::40d1:40d8:1f50:300c%16
Autoconfiguration IPv4 Address: 169.254.48.12
Subnet Mask: 255.255.0.0
Default Gaeway:

Steps I've taken to try to resolve problem (I did try to fix this myself before posting here via hours of going through page after page of people having a similar problem so isn't me just being lazy):
-Change ethernet cable
-Reset DHCP client in services
-Banging my head on the keyboard
- Tried running netsh int ip reset in cmd but ain't 100% sure as this is what I get:
Resetting interface, ok!
Resetting neighbor, ok!
Resetting path, ok!
Resetting, failed.
Access is denied.

Resetting, ok!
Restart the computer to complete this action


Really hope someone can help me out (I game on my desktop so this means no online gaming for me for the time being till this is fixed), cheers me in advance.

 

[Albino Boo]

You are not getting a DHCP address from your router. The 169.254.xxx.xxx is an IP address range that windows defualts to when not picking a DHCP address. The easiest way around this is set a static IP address on your desktop. Look up your laptop IP address and give your desktop the next ip address up.

 

[Frankster]

snip

Thank you very much for your response!
Alas still not working, will go over steps i've done in case i messed something up.

1) Used the cmd application on laptop, typed ipconfig/all and took note of the following:
IPV4 Address: 192.168.0.2 (preferred)
Subnet mask: 255.255.255.0
Default Gateway: 192.168.0.1
DHCP server: 192.168.0.1

DNS Servers: 192.168.0.1

2) Went over to my desktop, navigated to Network and internet>network connections.
Right clicked on "ethernet" and into properties.
Right click on "internet protocol version 4 (TCP/IPv4) and into properties and did the following:
Use the following IP address:
IP address: 192.168.0.3 (since you told me to use the next one up)
Subnet mask: 255.255.255.0
Default gateway: 192.168.0.1
Use the following DNS server addresses:
Preferred DNS server: 192.168.0.1

Tick "validate settings upon exit" as I finished up.

3) Window Network diagnostics started running and looking for problems in network configuration,does its usual dance routine before asking me to go investigate router or broadband modem issues, so i go ahead and reset the router before clicking "check to see if problem is fixed", takes longer then usual before finishing on "The default gateway is not available".

So we went from "ethernet doesn't have a vaid IP configuration" to "the default gateway is not available", an improvement of sorts I guess.

What to do next? >_<

 

[Albino Boo]

Ok next step

On your desktop open cmd and type
ping 192.168.0.1

and then type
ping 192.168.0.2

If you get a reply from 192.168.0.2 but not 192.168.0.1 means the problem likely to be in ICS

http://windows.microsoft.com/en-gb/windows/using-internet-connection-sharing#1TC=windows-7
run through that guide to make sure the setting are right.


If you don't get a reply from 192.168.0.2, I suspect that the problem is with the firewall settings on your laptop.

 

[Frankster]

snip

Oh boy you're gonna love this...Neither of them got a reply, same message for both x4:
"Reply from 192.168.0.3: destination host unreachable"

Followed the steps in that guide, everything seeemed ok on host laptop right down to wireless internet having the share connection box ticked.

Did the same on desktop, including the step of selecting "obtain an IP address automatically" which we changed in a previous step, and the "ethernet doesn't have a valid IP configuration" message returned. I promply changed the settings back to the way we did it previously so we are back at "the default gateway is not available".

For gods sake this net connection was working fine until recently xD I swear I haven't messed with it in any way.

 

[Total LOLige]

If all else fails you could try restoring Windows to a system restore point the day before you started having this issue. I think it should work, it'll save time rather than racking your brains for hours over what the problem could be. Rather defeatist, I know.

 

[Frankster]

snip

As it turned out I did have a restore point a few days just before net stopped working.
But alas, system restore didn't fix the problem, we are back to "ethernet doesn't have a valid IP".

So.....What next? xD By this point I'm considering making sacrifices to the dark gods of technology.

 

[Frankster]

Thank you for all your help guys but I think it's obvious by this point this is one of those pain in the rear end problems that can only be fixed with sweat, blood and tears by someone who can physically mess around with the computer.

So taking it to a shop and will hope they can sort it out without being too pricey. Cheers again for the help given, it's very much appreciated!

catchpra: raise chin. Oh it's ok catchpra I can make do without my fancy computer and its awesome games for a while longer.

Update: Was told to go phone my net provider, wish me luck as I attempt to get tech support from a foreign dude whose accent I will barely understand (speaking from experience here).

Update 2: Well at least I got to speak to Scotty from star trek so understood the guy.
Sadly he couldn't help me out. So in conclusion:

-Shop tells me to go call net provider
-Net provider can't help.
-?
-Profit

Update 3: Got a bigass cable, will make holes in the wall later this week and plug desktop directly into the router. Some would say i should have done this from the start and they have a point. Anyways guess I'll never know what went wrong but so long as my desktop gets its net back in a week it doesn't matter too much. Again, thanks to everyone who posted for their time.