What is the first step for a system administrator to set the server into BIOS mode when installing an OS?

The first step in setting a server into BIOS mode when preparing to install an operating system is to power on the server. This action initiates the server's startup sequence, allowing the system to begin the boot-up process. During this process, the system performs initial checks and prepares the hardware, setting the stage for the administrator to access BIOS or other firmware interfaces.

Once the server is powered on, the system administrator can then enter the BIOS, where they can configure various hardware settings, including boot options. This step is fundamental as it is a prerequisite for accessing the BIOS settings necessary for operating system installation.