Error 0x800706BA — RPC Server is Unavailable

Error 0x800706BA: The RPC server is unavailable

This error occurs in: Windows Server 2016, Windows Server 2019, Windows Server 2022.

Cause

The network firewall on the KMS server is blocking TCP port 1688, or the DNS SRV records point to a non-existent or unavailable KMS host.

Symptoms

• During activation, the message appears: "The RPC server is unavailable"
• Error code: 0x800706BA
• English version: "The RPC server is unavailable"

Step-by-Step Solution

On the KMS server: add an exception in the firewall for TCP port 1688. Check the DNS SRV records. Verify the availability of the KMS server: Test-NetConnection <kms_host> -Port 1688.

Solution for Windows Server

1. Open PowerShell as administrator
2. Enter the key:

slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

1. Activate:

slmgr /ato

1. Check the status:

slmgr /xpr

Verification

After performing the steps, check if the activation was successful:

• Windows: Settings → System → Activation → should be "Windows is activated"
• Or: slmgr /xpr in the command line

Still not working?

If the above steps did not help:

1. Check the date and time — they must be correct (an incorrect date can block activation)
2. Temporarily disable the antivirus and try again
3. Check the internet connection — online activation requires a connection to Microsoft servers
4. Contact us:
   • Email: [email protected]
   • Phone: 00 800 121 1654 (free)
   • Help centre: pomoc.kluczesoft.pl