Halo Reach maxing out my cpu constantly.

Processor Intel(R) Core™ i5-7300HQ CPU @ 2.50GHz, 2501 Mhz, 4 Core 4 Logical Processor

Geforce 1050ti

Windows 10

16 gb ram

Attempting to play on performance setting at 1080 at 60 fps.

So by no means a great system but I am playing outerworlds and numerous other games daily. However Halo Reach cannot maintain a playable framerate.
I have tried it with Vsync on and off, set the settings to performance and set the frame rate to 60. However the frame rate is just all over the place and although my GPU seldom exceeds 40% my CPU is pegged at 100%, occasionally dropping into the 90’s.

Steps I have taken
Updated the driver with Nvidia experience to the latest, supposedly optimized for reach version.
Checked that the game is using my 1050ti by checking with after burner.
Played a few other games on same HDD just to ensure the system is performing as normal.

Not really sure what else I can try as it does not seem to be the system, I am as above playing a bunch of other games on a daily basis and having no such trouble.
Any ideas welcome as this has me a little stumped.