That´s a very low end system and it might be normal for it.
While windows is freshly installed, it might need some time to update itself quite a while.
Check the ressource manager, which process exactly is using the CPU.
You can check with passmark, if the system works normal or not.
AMD.com drivers installed for this system?
Is it a Laptop? Which brand and model?
edit: in the image you posted, AVAST was installing, this could be it. Just let it install/update and have a look if it gets better over time.