It seems odd but after this update the media streaming options were turned off, I had to turn it back on before
I could access my media stored on the PC from my TV. First time I've seen this. Coincidence?

Surprised to see this update on this date. Something important it had to be out of band?

I'm running an older AMD processor, the 4300 FX. It's unclear to me from what I've read
whether I'm going to take a performance hit or not. The following quote implies that AMD is not affected.

Thomas Lendacky, a member of the Linux OS group at AMD, posted the following over at LKML:
AMD processors are not subject to the types of attacks that the kernel page table isolation feature protects against. The AMD microarchitecture does not allow memory references, including speculative references, that access higher privileged data when running in a lesser privileged mode when that access would result in a page fault.

Brink said:

You could run the PowerShell script from below to see what it reports to help be sure.

Windows Client Guidance against speculative execution vulnerabilities - Windows 10 Forums

Interesting here's my output. It says hardware support is not available and Windows support is not enabled.
Guess that makes sense. Do I have to now do something to "undo" anything powershell did ?
I do have a system restore point set I did just prior to it's use.

PS C:\Windows\system32> Set-ExecutionPolicy Unrestricted -Scope Process -Force
PS C:\Windows\system32> Install-Module SpeculationControl -Force

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PS C:\Windows\system32> Get-SpeculationControlSettings
Speculation control settings for CVE-2017-5715 [branch target injection]

Hardware support for branch target injection mitigation is present: False
Windows OS support for branch target injection mitigation is present: True
Windows OS support for branch target injection mitigation is enabled: False
Windows OS support for branch target injection mitigation is disabled by system policy: False
Windows OS support for branch target injection mitigation is disabled by absence of hardware support: True

Speculation control settings for CVE-2017-5754 [rogue data cache load]

Hardware requires kernel VA shadowing: False

Suggested actions

* Install BIOS/firmware update provided by your device OEM that enables hardware support for the branch target injectio
n mitigation.
* Follow the guidance for enabling Windows support for speculation control mitigations are described in https://support
.microsoft.com/help/4072698


BTIHardwarePresent : False
BTIWindowsSupportPresent : True
BTIWindowsSupportEnabled : False
BTIDisabledBySystemPolicy : False
BTIDisabledByNoHardwareSupport : True
KVAShadowRequired : False
KVAShadowWindowsSupportPresent : True
KVAShadowWindowsSupportEnabled : False
KVAShadowPcidEnabled : False



PS C:\Windows\system32>