What must you do in disk management so that windows explorer can recognize and use a new hard disk?

In Disk Management, you must first initialize the new hard disk by right-clicking on the unallocated space and selecting "Initialize Disk." After initialization, create a new volume by right-clicking on the unallocated space again, choosing "New Simple Volume," and following the prompts to format it and assign a drive letter. Once this process is complete, Windows Explorer will recognize and allow you to use the new hard disk.