Ezbcd chooses what it wants as far as the ezbcd ID
These ids are not generated by EasyBCD,
The BCD UID is generated by Windows and is a hashed combination of the unique device signature and the partition offset from the beginning of the device and it's stored in the registry
EasyBCD translates the letter you specify by referencing the Registry map of Windows disk letters/UIDs to find the correct ID for the partition you want.
The BCD doesn't contain Windows disk letters at all.
The Windows disk letters you see in EasyBCD "view settings" (both versions) are additional translations from the map in the registry of the running OS, reported to you by EasyBCD because the actual IDs are so human unfriendly.
If EasyBCD is telling you that that's the ID for disk letter E, it's because that's how it's mapped in your registry, and that's the only way you can find it.
You can see it in Regedit HKEY_LOCAL_MACHINE > SYSTEM > Mounted Devices > \DosDevices\E
It's not a field you can edit, because EasyBCD only communicates with the user in Disk letters via that registry map, hence "Easy.." doing all the hard translation work into that finger-trouble-prone format for you.
If there were anything wrong with that BCD entry (as there would be if you changed anything) the boot with fail with some kind of "..not found " message.
The fact that it tries to do something and fails indicates that more is wrong with your system than just the lost boot sector.
The boot sequence is
1.After pressing the power button, the PC’s firmware initiates a Power-On Self Test (POST) and loads firmware settings. This pre-boot process ends when a valid system disk is detected.
2.Firmware reads the master boot record (MBR), and then starts Bootmgr.exe. Bootmgr.exe finds and starts the Windows loader (Winload.exe) on the Windows boot partition.
3.Essential drivers required to start the Windows kernel are loaded and the kernel starts to run, loading into memory the system registry hive and additional drivers that are marked as BOOT_START.
4.The kernel passes control to the session manager process (Smss.exe) which initializes the system session, and loads and starts the devices and drivers that are not marked BOOT_START.
5.Winlogon.exe starts, the user logon screen appears, the service control manager starts services, and any Group Policy scripts are run. When the user logs in, Windows creates a session for that user.
6.Explorer.exe starts, the system creates the desktop window manager (DWM) process, which initializes the desktop and displays it.
which would indicate, since you didn't get a winload.exe not found message, that something failed in 3 or 4, before any monitor activity in 5
If this happened because of a failure in Windows Update, then you're entitled to free one-to-one support from Microsoft to fix it
Start here
https://support.microsoft.com/en-us/help/10164
and I think the walk through should end with a Telephone help number if the intervening steps don't help
