Can't open boot меню after installing mainlline kernel

Because of крах вирусы I experienced on my Делл Инспирон, бve downloaded and installed в mainline kernel (this one), and the process run smoothly and without any errors.

Following these instructions, after installation the kernel should be offered схвати в boot option on start-up. But when I restart my laptop, it boots automatically into the регулярный Ubuntu system, and not entering any boot-меню I хан choose from.

How хан I enable such меню?

Thanks.