how can i get full access of bios settings in my acer aspire lite

No, You can't access that and you shouldn't be trying to unlock it with any unofficial methods.

Laptop BIOS settings are often limited by manufacturers primarily to ensure system stability, compatibility, and security. By restricting access to certain options, companies can prevent users from making potentially harmful changes that could lead to system failures or incompatibility with hardware components. Additionally, these limitations help protect against unauthorized modifications that could compromise security, such as BIOS rootkits. Since many laptops are designed for general consumers rather than tech enthusiasts, manufacturers focus on providing a streamlined experience, omitting advanced features like overclocking and extensive customization that may not be relevant for the average user.