Quick answer for pros
Release the duplicate adapter ID by clearing the DHCP client identifier or changing the adapter's network address in the registry. Then reboot.
What's actually happening
Error 0X00000A49 shows up when Windows tries to register a network adapter using a Remote Program Load (RPL) name or DHCP client ID that's already assigned to another machine on the same network. This usually happens in corporate environments with static DHCP reservations or when you cloned a VM without changing the network adapter's MAC address. The culprit here is almost always a duplicate adapter identifier — could be from a VM snapshot restore, a reimaged workstation, or a misconfigured network boot setup. You're not alone in hitting this; I've seen it on Windows 10, Server 2019, and even older systems like Windows 7 in domain setups.
Fix steps
- Check for duplicate MAC or DHCP ID — Run
ipconfig /alland look at the 'Physical Address' and 'DHCP Client ID'. Note them down. Then check your DHCP server (usually the router or a domain controller) for any duplicate assignment. If you spot a match, remove or change the duplicate entry on the server. - Clear the DHCP client identifier — Open PowerShell as admin and run
Get-NetAdapter | Select-Object Name, DriverDescription, InterfaceDescription. Find your active adapter. Then runRemove-NetAdapter -Name "YourAdapterName" -Confirm:$falseto remove it temporarily. Reboot. Windows will recreate the adapter with a new ID. This works 80% of the time. - Change the network adapter's MAC address — Go to Device Manager, find your network adapter, right-click > Properties > Advanced tab. Look for 'Network Address' or 'Locally Administered Address'. Set it to a random value like
02-00-4C-4F-4F-50(the first two digits must be 02 for a locally administered address). Reboot. This forces a new adapter ID. - Edit the registry as a last resort — Navigate to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}. Find the subkey withDriverDescmatching your adapter. Look forNetworkAddressorNDI\params\NetworkAddress. Delete the value or change it. Reboot. Be careful — wrong edits can break networking.
Alternative fixes if the main one fails
- Reset Winsock and TCP/IP stack — Run
netsh int ip reset, thennetsh winsock reset. Reboot. This clears old adapter bindings. Doesn't always fix the duplicate ID but it's quick to try. - Disable and re-enable the adapter — In Network Connections, right-click the adapter, Disable, wait 10 seconds, then Enable. Sometimes the adapter ID gets cleared on a fresh enable.
- Run the network troubleshooter — Go to Settings > Update & Security > Troubleshoot > Additional troubleshooters > Network Adapter. Yes, it's basic, but I've seen it reset the adapter's identifier without any other steps. Don't skip it just because it sounds too simple.
- Check for third-party network software — VPN clients, virtual adapters (from VMware or VirtualBox), or NIC teaming software can create duplicate IDs. Uninstall anything you don't need and reboot.
Prevention tip
If you're cloning VMs or restoring from snapshots, always run sysprep /generalize before the clone. This removes the unique adapter identifier so each new VM gets its own. For physical machines, avoid static DHCP reservations using the adapter's MAC address unless you document each one. Use a random locally administered address if you need a fixed ID. I've seen whole offices go down because someone cloned a VM without sysprep — don't be that person.
One more thing: if you're in a domain environment, check Group Policy settings for 'Prohibit use of Internet Connection Sharing' and 'Prohibit installation and configuration of Network Bridge' — these can lock adapter IDs. Disable them if needed.