Final answer:
The technician should use the command 'bootrec.exe /fixmbr' to repair the corrupt master boot record on a Windows 10 laptop after booting from the installation media into the command line interface.
Step-by-step explanation:
To repair the corrupt master boot record (MBR) on a Windows 10 laptop, the technician can use the bootrec.exe /fixmbr command. This utility is available when you boot from the Windows installation media and enter the command line interface (recovery environment). The bootrec command is a tool provided by Windows that can be used to repair the MBR, boot sector, or add missing Windows installations to the boot configuration data.
It's worth noting that chkdsk is used for checking the integrity of files and file systems, format is used to format a drive, and sfc (System File Checker) scans and repairs protected system files. These commands serve different purposes from the bootrec.exe utility, which is specific for boot-related issues.