I have the very same question. I did multibooting for a while and have lots of false/redundant boot entries in BIOS, can I remove all of them and create a fresh bcdentry?
I tried all kinds of tools to no avail, EasyBCD, EasyUEFI, etc.
This quick and dirty fix worked for me on Windows 10 UEFI boot.
Go into the BIOS settings and set everything -- all disks, storage devices etc -- to Compatibility mode/Legacy boot.
Reboot and let it fail to load Windows, returning you to BIOS.
Now re-enable UEFI boot, restoring the settings you had before.
Voila, everything is erased from the boot sector except for Windows.
I used this method so I could do a Physical-to-Virtual (P2V) conversion of my hard disk, so I could use it in a virtual machine. If you don't clean the boot sector, the virtual machine might boot to grub, and it's hard to correct that.
The right way to do it is to convert a clean boot sector.
I found another way to get rid old boot entries in UEFI by using the program DiskGenius which can found at this link How to manage EFI/UEFI boot options with DiskGenius Free from Windows? I tried the programs mentioned by other users and none worked but this one
Hi there
@dictum
@logictonic1
Another way
Boot up any UEFI Live Linux distro and then ensure you have efibootmgr installed on it. (Or those that have dual boot with Linux -- boot into that - also ensure efibootmgr is installed).
now run the efibootmgr command and you'll see a list of boot entries for example in my case :
delete the HEX number(s) of the boot entries you want to delete
Job done --even easier !!!!!
Cheers
jimbo
Last edited by jimbo45; 06 Jan 2020 at 04:59.
I removed all entries (using the command provided in Clear up BIOS boot menu entries |Article:197/257, Chan:7616205 |RSSing.com" or YouTube), and the available ones are re-created automatically after next boot. I have to do this task often, so I wrote this PS-Script (see attachment) to automate the job of removing them all. Feel free to use it.
Hi there
Most of the Windows solutions only remove entries from one disk -- if you use the Linux method (efibootmgr) that I posted about 3 posts back it will show all UEFI boot entries on ALL the HDD's in your system.
If you only have 1 HDD / SSD OK -- but a load these days have machines with often 4 or 5 HDD's .
Cheers
jimbo
All the BIOS does is read (via hardware program in the eprom / ROM) the appropriate HDD's for a bootloader and then bootstraps a sector of an appropriate bootloader (either by default or by BIOS user menu) into a specific area of memory which contains the rest of the code to load the program. Control of the next instruction is passed to the address in RAM where the bios has loaded the "Bootstrap code" and execution continues as per any other application.
That piece of code then "loads the OS" and continues as normal e.g logon screens etc etc.
Even IBM mainframes start up that way --hardware switch has one instruction to load data from bootdevice boot sector, that sector contains enough code to start to load the OS and continue -- so you need basically 2 instructions in BIOS to start the entire OS.
Cheers
jimbo
I know that but bootstrap has to load at least part of OS kernel to even show BOOT menu. UEFI BIOS itself is not changed at all, It has own boot order list for physical drives.
BOOT order shows all bootable devices which in UEFI mode shows as something like this
"Windows UEFI BOOT on such and such disk"
I can show you a picture of it in my BIOS.
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