From EasyBCD KB:
"After booting into a working copy of Windows and running EasyBCD, selecting “Re-create/repair boot files” on “BCD Backup/Repair” page, then “Perform Action” to begin recovery, EasyBCD will recreate (if possible) your boot files and re-configure your bootloader from scratch."
When I do it in Win8.1, EasyBCD performs all the action with current normally working disk & volume without offering me another drive to choose!
"Go to “Bootloader Setup” window, select “Install Vista/7 Bootloader to MBR” from the second menu, then click “Write MBR”
(Note – the first section applies to External Devices (e.g USB flashdrives). Do not use it on your HDD)".
The 1st section may also apply to internal drives. In my system there are several disks, and each can be switched on and off any time, or boot disk changed in BIOS, so the next boot will be from another physical internal disk, while the 1st one will still be p[resent in the system.
In the 2nd section, it would be nice if EasyBCD offer a dropdown menu to choose the HDD to write chosen MBR to. In most cases its likely needed for another HDD present in the system, not the one just nicely booted from. In any case, the destination drive should be clearly spelled out to a user to avoid confusion and errors.