A technician is upgrading a computer OS from Windows 7 to Windows 10.

Loading the hard disk drive (HDD) drivers using a flash drive is the most likely action that can fix the issue of a computer not being able to find the hard drive during an OS installation from Windows 7 to Windows 10. The HDD may have a different interface or controller than what Windows 10 supports by default, such as SATA or RAID, which would require loading additional drivers during the installation process. The technician can use a flash drive to load the drivers from another device or source. Changing the partition to MBR, upgrading the RAM modules, or replacing the hard drive are not likely to fix the issue, as they are not related to the HDD drivers