How to restore grub2 menu?

Question

linux

The problem is the following.
The laptop has 2 win systems installed (first of all), and then ubuntu.
When enabled, ubuntu is loaded.
I watched a bunch of videos and articles. Everywhere requires an installation disk / flash drive, to which I do not have access.
Is it possible to simply return Grub from the system itself?

Answer 1

Nifiga did not understand. What's the problem then? What to return? If ubunta is loaded, then all the norms of
Windows are in the hornbeam or something?
fdisk -l
It will give you a list of partitioned devices. Look for where NTFS is, then in the hornbeam config, stupidly write a line with Windows and a partition with NTFS.
Can you google where the hornbeam config is? :D
Well, you are bone-speaking Windows users, who for some reason installed ubuntu since they don’t need it .....

Answer 2

Put on ubuntu Grub Customizer, he will find windows.