Apparently this is a rare occurrence (Win7 & Wind 10),

but, it does not hurt to check.

 

I Installed the Windows 10 upgrade and anniversary update on 1 of my computers.

This one is an older one (i7 950) not used for Flight Sim, but for charts and other tasks while flying.

 

The i7 950 is a 4 core (8 logical) processor, mine is HT enabled and after the update I lost 7 processors, so my CPU usage was 100% all the time.

 

I was about to roll back to Windows 7, but checked some stuff and CPU-Z

was reporting only 1 active core. ?????

 

1. Device Manager showed the 8 logical processors.

2. Windows 10 reported and used only one processor in Task Manage -> Performance -> Graph (Logical Processors option was Disabled)

3. MSConfig showed only 1 processor P0 in Boot -> Advanced Options.

4. Processor Affinity was only showing CPU 0.

 

 

Found Solution here:

HOWTO: Get Windows 7 to detect your new multi-core processor.

(It states Windows 7 but worked fine with Windows 10)

 

Basically what the document says is:

1. Uncheck Number of Processors in MsConfig -> Boot -> Advanced options.

2. Download EasyBCD for Window 10. (BTW this is Great Dual Boot Utility)

3. Run EasyBCD -> Advanced Settings -> Developer and -> Check Windows CPU/core Limit, making sure it is 0 -> Save Settings

4. Reboot.

 

You should then be able to show all CPU logical processors in Task Manager -> Performance.and in MSConfig -> Boot -> Advanced Options. Also CPU-Z will report correctly.

 

So: Make sure You have all your processors running.

Note: This is not the same as parking processors.

 

Hope this helps someone.

 

Cheers.

Wow, crazy the update caused such an issue for some.