What can cause reduced available disk space on a newly installed hard drive?

Reduced available disk space on a newly installed hard drive can indeed be attributed to manufacturers' conversion discrepancies in storage reporting. Hard drive manufacturers define storage capacity using the decimal system, where one gigabyte (GB) equals 1,000,000,000 bytes. However, most computer operating systems calculate storage using the binary system, where one gigabyte equals 1,073,741,824 bytes (2^30 bytes). This discrepancy results in hard drives appearing to have less available space than their labeled capacity when viewed in an operating system. For example, a drive marketed as 500 GB may show approximately 465-470 GB of usable space in the OS due to this difference in calculation.

Unallocated space for system recovery, partitioning the drive into multiple volumes, and reserved space for future updates by the OS can also impact usable disk space, but they are not as universally applicable as the conversion discrepancies. Unallocated space typically is space that has not been assigned to any partition, and while it can occur, it’s generally not an expected characteristic of a newly installed drive unless misconfigured. Partitioning can seek to maximize disk utilization but can lead to fragmented space if not managed properly. Reserved space for OS updates, while important for system functionality,