Windows Mobile update unsuccessful - Update server was not available

Hi

I am trying to update my windows mobile which is i786 samsung , I goto settings, system then windows update, it try to update but in the end says that
Connection to update server was not available. Check your data connections settings and ensure the device date and time are correct

But my phone's date and time are correct and internet settings are also good becuse I can access internet on it but still it is not working.

I dn't think you can update windows mobile directly. Because you are using samsung, you should only use Samsung's official update. It is because they provide updates specially optimized for the their own phones.