When a Windows computer which is an Enterprise Client, receives Volume Activation Error No records found for given DNS query 0x8007251D, it means that there is some issue with the network.

In order to stay activated with a KMS key, you need to connect with your Enterprise at least once in 180 days. However, if even after connecting for two hours ( which is the max time KMS sever takes to keep the device activated), it's not able to find the DNS records, you need to troubleshoot your network.

You can use DNS FLUSH, IP Reset, and even restart your Windows 10 computer to fix those small network issue. Windows 10 also comes with inbuilt network troubleshooter which you can try as well.

If nothing works, then make sure to connect with your admin, and ask him to figure it out for you. Sometimes it's server issue which only they can resolve.