Hi,
According to your description, my understanding is that Windows 8.1 failed to connect to Essentials with Event ID 1309 and 53.
Which stage does the problem happen? And what is the error message? Such as access http://server/connect via browser prompts error, connector download failed, or failed when running Connector Configuration Wizard?
Event ID 1309 seems to be a .net related problem, open Control Panel\Programs and Features to confirm the .net version that has been installed. Also, confirm that TCP/IP over NetBIOS is enabled on TCP/IP properties.
Event ID 53, reference link below to narrow down this problem:
https://technet.microsoft.com/en-us/library/cc726352(v=ws.10).aspx
Best Regards,
Eve Wang
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