You have an existing workstation computer in your local domain where you installed Windows manually. For some reason, e.g. hardware damage, you have to reinstall Windows.
Now you have a WDS / PXE server in your environment and you want to use it for the Windows reinstallation (install via network).
If you have installed Windows manually first, WDS will give the computer another name, but this is exactly what we don’t want – we want the same computer name as it had before. But usually, you are not asked for a computer name during the WDS installation process.
If you have configured WDS to manually accept devices before booting, you are able to give the computer a certain name via WDS console before it boots, BUT it will not accept is if the computer name already exists in AD (which it definitely does in this case).
Because of the initial manual Windows installation, the AD computer object of the workstation misses an attribute called netbootGUID. WDS needs this to identify machines.
You could delete the computer from your AD console and then set the „new“ name again via WDS, but imho this is not a good solution. You would e.g. lose GPO settings if you have set any special ones for this certain devices.
So the better way is to insert the netbootGUID value in the Active Directory computer object before you reinstall Windows via PXE.
Open your AD Users and Computers console, open properties of your computer object and go to tab „Attribute Editor“. Then search for attribute „netbootGUID“. If it doesn’t exist, create it.
Then enter the netbootGUID value (hexadecimal). If you do not want to type it, you can e.g. export the „pending devices“ view from WDS and then copy it via Notepad. You also see the netbootGUID when you boot via PXE.
Finally, you can install Windows with your WDS image. It should not ask for a computer name and give the machine the right one.