. . . . How to turn on Hardware Acceleration when creating Mp4 . . . .
We need more information on your computer specification - see this topic for details of what is required.
In general for Hardware Acceleration (HWA) Photostory VR requires an Intel processor with integrated GPU (iGPU), if you have an AMD processor HWA will not be available to you.
If you have a NVidia or AMD graphics card installed with an Intel processor then the iGPU may be disabled.
You will notice I have removed a couple of posts and combined the information and removed superfluous data from the other. There is no need to create multiple posts in the same topic - the input box is capable of holding very long posts with images, short video clips and text in the one post.
It would help for future reference, if you put your computer and software details in your Signature - see mine for an example.
The important data for the issue you are having is:
Intel Core i7-3630QM, NVIDIA GeForce GTX 670MX
The Intel processor does not have a suitable integrated graphics chip - HWA requires a 4th generation or later processor and the GTX 670 cannot not be used.