[Rehan]

Hello experts,
                    A few days i was trying to install PrimeOS in Windows 10 for a dual boot. I failed to install it from a .exe installer. i thought maybe the installer i downloaded is corrupt so i decided to install it via an ISO. i made a bootable USB and tried to boot it with Legacy boot. but still i failed to install cuz of some technical errors. Than i tried to boot it with UEFI boot, but it was still showing the same error. I decided to use an emulator instead of installing a OS.I cancelled the installations. Now whenever i go to Dell Boot menu under UEFI boot a option " PrimeOS " is always available. while i have tried deleting the partition i used to install this OS. i have deleted the 100MBs system reserved partition so it may remove this from boot menu. But it is always there.When ever i click it. it returns to boot menu. What is the actual problem?

https://i.imgur.com/WvY0Et8.jpg

[Mashiro]

The primary Windows operating system was installed in legacy mode. There is no detection of the operating system in the BIOS / EFI / UEFI (legacy). You can only see the hard drive name.

Now to the problem ... The installation of the new operating system was attempted in UEFI mode. In this mode, the operating system can be recognized or the operating system itself can make such entries in the UEFI BIOS boot menu (such as seen in your screenshot).

Please note: Deleting the operating system and / or the partitions of the operating system will NOT remove the entry in the UEFI BIOS. This entry can (e.g.) be removed by completely resetting the UEFI BIOS or it will be overwritten with the installation of another operating system in UEFI mode. Since you have now deleted the operating system or the partitions from it, the entry "PrimeOS" now points to nothing. Therefore, the boot menu always goes back to the beginning.


P.S.: Some of your steps were careless and thoughtless. Removing partitions from other operating systems can cause problems. The 100 MB partition (Windows 7?) can cause problems when deleted. I already had experience with it. Windows has not started up after deleting this partition. Fortunately, the solution was quite simple. Started from a Windows DVD, opened the command line and reinstalled the Windows boot loader or overwritten the old installation (rather said).

[Rehan]

Please note: Deleting the operating system and / or the partitions of the operating system will NOT remove the entry in the UEFI BIOS. This entry can (e.g.) be removed by completely resetting the UEFI BIOS or it will be overwritten with the installation of another operating system in UEFI mode. Since you have now deleted the operating system or the partitions from it, the entry "PrimeOS" now points to nothing. Therefore, the boot menu always goes back to the beginning.

First of all i will thank you for replying me. and now i will ask you, how can i reset the UEFI BIOS? Do i try to reset system setup settings to default? or any different mechanism to reset UEFI BIOS?

P.S.: Some of your steps were careless and thoughtless. Removing partitions from other operating systems can cause problems. The 100 MB partition (Windows 7?) can cause problems when deleted. I already had experience with it. Windows has not started up after deleting this partition. Fortunately, the solution was quite simple. Started from a Windows DVD, opened the command line and reinstalled the Windows boot loader or overwritten the old installation (rather said).

Yea you are right, that caused some problems. I was aware of it. I made a backup before doing that. : Actually primary OS was in need of re-installations because of the failed installation from .exe were also showing options at startup. I know that was not the solution but i did that.

[Mashiro]

First of all i will thank you for replying me. and now i will ask you, how can i reset the UEFI BIOS? Do i try to reset system setup settings to default? or any different mechanism to reset UEFI BIOS?

Such an option in your BIOS/EFI/UEFI would be usually called "Load default values" or similar. Another option is to perform a CMOS reset (either through a switch on the mainboard, a jumper or by removing the CMOS battery).

Please keep in mind that the OS information might also be just written on the disk itself if a BIOS reset doesn't remove it (MBR/GPT partition table entries). In that case you might really have to wipe the whole disk and also install a new OS in UEFI mode. The BIOS handles legacy mode installations different than UEFI. These are two seperate things.


Beware: A CMOS reset or the loading of default values will wipe all custom settings in your BIOS/UEFI! This might lead to more issues if you had things setup in a certain work. Be careful with what you do. You're doing everything at your own RISK!

[Rehan]

Thank you @HR for solution. I have successfully removed it. I restored settings to default but it was still there. It was very simple. Under the boot sequence i removed PrimeOS option in UEFI Boot option and then returned to Legacy mode and successfully booted my Windows.

[humanpuff69]

The primary Windows operating system was installed in legacy mode. There is no detection of the operating system in the BIOS / EFI / UEFI (legacy). You can only see the hard drive name.

Now to the problem ... The installation of the new operating system was attempted in UEFI mode. In this mode, the operating system can be recognized or the operating system itself can make such entries in the UEFI BIOS boot menu (such as seen in your screenshot).

Please note: Deleting the operating system and / or the partitions of the operating system will NOT remove the entry in the UEFI BIOS. This entry can (e.g.) be removed by completely resetting the UEFI BIOS or it will be overwritten with the installation of another operating system in UEFI mode. Since you have now deleted the operating system or the partitions from it, the entry "PrimeOS" now points to nothing. Therefore, the boot menu always goes back to the beginning.


P.S.: Some of your steps were careless and thoughtless. Removing partitions from other operating systems can cause problems. The 100 MB partition (Windows 7?) can cause problems when deleted. I already had experience with it. Windows has not started up after deleting this partition. Fortunately, the solution was quite simple. Started from a Windows DVD, opened the command line and reinstalled the Windows boot loader or overwritten the old installation (rather said).

reinstallling the bootloader is the best way . it doesnt do data loss and your system basically back to normal . but i think microsoft should include an easy way to fix it . most people that doesnt know the way probably just reinstall it and it will probably/will be destroying all the data and cause a data loss