Is it possible to update the windows bootloader in my operating system without a boot disk or flash drive?

Question

System administration

Good day! tell me please, I have two OS windows, ubuntu. I want to demolish ubuntu since the old version was installed clumsily, I found an option to update the windows bootloader, after already through windows remove ubuntu, the article states to start windows through the installation disk and write in the command line bootrec /FixMbr then bootrec /FixBoot update the default bootloader. Can I just run the command line in the installed windows and do all the steps there without an installation disk or flash drive? not how not to damage windows or its files, thanks in advance

Answer 1

1) Create a bootable flash drive, for example with AdminPE and backup the entire system disk. For example in Image For Windows. Whole.
2) Put Windows on it, with the removal of partitions, outright. Until the desktop. Do not need anymore.
3) Again return your old Windows from the backup, but only drive C: - overwrite with your old ones - fresh. Only one section.

Answer 2

Yes. you can, from under the administrator, the
boot block is not used in any way when the system is running and can be redone at any time. the main thing is to do everything right.