My laptop DELL PRECISION 3530 has 1 TB SSD. I installed 3 OS. First Windows 10, then Linux mint 19 and then Ubuntu 18. During the installation I had to straggle in the BIOS option. This laptop has option UEFI option. I didn't know anything about it. If UEFI and secure boot enable. When I bootup with the either Mint Linux or Ubuntu Linux, it doesn't show me my unallocated space. I was totally confused. Then I asked a question about it here:- Mint Linux can't find unallocated ssd disk sapce
Anyway later I disable UEFI option and turn on legacy option in BIOS. After that I can see my total SSD and all space. Then I installed Mint and Ubuntu. But after installation. I was expecting that there will be a boot menu to select which OS to bootup. Now it doesn't show any boot menu at all. Here is pic of GParted :-
Please tell me how can I get the boot menu to boot any of the OS?
I found the actual issue. It is mainly BIOS setup for the latest model laptops comes with UEFI and secure boot options. I had to follow the following options:
Then boot the Linux infestation by DVD or USB. Well, the latest laptop comes without any CD/DVD ROM.
Now you should see the whole SSD. To verify it just lunch GParted. Thanks to GabrielaGarcia for helpful suggestions.