Remove Ubuntu from duel boot configuration with windows 11

 go to recovery

restart windows and go to uefi

select windows boot manager and position it above ubuntu entry

restart

delete all ubuntu partitions using diskmgmt.msc

then

> diskpart  
> list disk       # select the primary disk
> select disk 0   # disk 0 is
> list partition   # a list of partition is opened

Note-> Check which is the system partition (example partition 1 is system partition)

> select partition 1  #select the system partition
> assign letter=x     #disk is now mounted in your explorer verify with (windows+E)
>exit    #exit from diskpart
>x:      # this would select this newly mounted disk x:
> dir  # displays content
> cd efi
>dir   #displays content

Note-> You can now see the OS check your Linux OS

>rd ubuntu /S    #if Linux os is Ubuntu
>y               #to confirm delete

 

 

Source:https://askubuntu.com/questions/921046/how-to-remove-ubuntu-from-boot-menu-after-deleting-ubuntu-partition-in-windows