odd static/assigned IP address getting stuck with old address

[thecompu-doctor]

This one is messing with my head. I think it should be a simple problem, but I'm just running around in circles chasing my tail.

I have a customers laptop, win 7 64bit pro. Was on a domain network with IP 192.168.15.64 reserved address. This was the hard line NIC connection settings.
It was recently move to a workgroup environment (yes it has been removed from the domain) to a new network. The wifi gets the new address 192.168.1.1xx from the DHCP router just fine. However, when plugging into the NIC, it still gets the old 192.168.15.64 address. I've uninstalled the NIC driver, verified that it is set to DHCP, run tweaking.com winsock repair tool, sfc /scannow, even set a proper static IP. However, it just can't communicate because even though it has this magic "DHCP" address, its not on the network.

Any ideas?

PS, i have not put my hands on it to do this troubleshooting. Its all been remote

 

[Moltuae]

Have you checked the Advanced settings in the adapter's TCP IPv4 properties for any DHCP/static configurations?

What does ipconfig /all say about the adaptor configuration?

 

[thecompu-doctor]

checked the advanced settings already and they came back set to default DHCP.

The IP config looks completely normal, except the IP address the ethernet is getting is 192.168.15.64, which nothing on the network is giving it that address.

 

[Martyn]

Will you post the ipconfig /all on here to look at? You've done the release, renew etc?

 

[Markverhyden]

ipconfig /flushdns then ipconfig /registerdns.

Have you gone through the properties page for the NIC to make sure not static values, such as DNS entries are there?

 

[Moltuae]

The DHCP info in ipconfig should give some clues.

Also, try this (run from an elevated command line):

netsh interface ip set address "Local Area Connection" dhcp

(replacing "Local Area Connection" with the adaptor name).

 

[kwisher]

Could the IP be a DHCP reservation that someone has forgot about? If you boot to a live Linux distro does it get the same IP? If so, I would suspect the DHCP reservation. If not, then it's a Windows issue somewhere.

 

[thecompu-doctor]

I want to thank everyone for their advice on this. After I finally made it on site, what it turned out to be was the patch cable in the network closet from the panel to the switch was plugged into the VOIP switch, not the network switch. Plugged it into the right switch and boom, all was well in the world. This also fixed the strange quickbooks problems she was having.