Thank you for keeping us posted. We've noticed that you've performed a few troubleshooting. We would like to clarify a few information so we can provide further troubleshooting or refer you to the right channel:
- Is your Windows 10 installed on the default Solid State Drive (SSD)?
- Did you change your default drive from an SSD to an HDD?
Because if what you're using is the default drive of your computer, be advised that the reason why ReadyBoost can't be used is that by nature, an SSD is already fast in terms of performance. That being said, you won't be able to get better performance by using the ReadyBoost feature.
We're looking forward to your response.