Dtyjlui

I've seen variants of this question on here, but so far none of the solutions I tried have worked.

I have an SSD with Windows on it, and an unallocated HDD that I want to run Ubuntu on. The windows SSD is in UEFI mode. I've heard that if I want to boot from Grub, I need ubuntu to also be in this mode rather than legacy mode. I went into BIOS and changed "UEFI+Legacy" to just "UEFI." I set up a usb using Rufus, it showed up as UEFI. I set it in BIOS as first priority and booted.

I chose "something else" in installation. I've tried many versions of the next step: partitioning the HDD as "/boot" and "/" and "swap." I've tried without the "/boot". I've tried without "/boot" and "/". I've also tried just normal installation "alongside Windows boot manager." In all cases the installation seems to work fine, and then it tells me to restart. I go into BIOS, but the HDD does not show up in UEFI mode, only if I change it back to UEFI+Legacy mode. If I then boot from this, depending on how I partitioned the hard drive, it either tells me "reboot or select proper boot device or insert insert boot media and press any key," or instead of this, there will be just a cursor on a black screen flashing forever until I turn off the PC.

Some have said that to fix the blinking cursor, I need to boot to this hard drive and hold shift to bring up Grubs and then edit a line, which will let me install needed drivers (I built my pc, I have an NVIDIA GPU, msi x470 motherboard, 16 GB RAM). If I do this, the screen comes up with "GRUBS..." and then nothing else after that. So I'm not sure how to make this edit.

I'm not sure if I'm partitioning incorrectly or what. I tried 1 Gb for /boot, 20 GB for swap, the rest for /. And other combinations. But even if I get Ubuntu to finally boot, I think my HDD will still be in legacy mode, so I wouldn't be able to boot both Ubuntu and Windows from Grub, I would have to change the priority every time I want to change operating systems. Am I supposed to check some box or something during installation to make it UEFI mode? I booted the usb in UEFI mode so I'm not sure if that was enough. But at this point I'm fine going into BIOS every time to change as long as I can at least get Ubuntu to finally boot. I've been playing with boot-repair but can't seem to get it to work, but maybe I'm not using it right.

If anyone has a solution to this, that would be great. Please let me know if more information is needed.

Your HDD needs to be partitioned using GPT not MBR which is usually the default, then the UEFI BIOS should find it ok. It's a good idea to use the Ubuntu disk partitioning tool in the Live disk to setup your partitions before you begin the install so it's easier to see what you're doing and where everything is going.

Also you need to set the first drive which I'm guessing is your Windows SSD as the location for the bootloader in the /EFI partition on the SSD (probably /dev/sda ). That way the installer will find your Windows boot files and let GRUB give you the option of which OS to boot.

On the subject of partition sizes, with 16gigs of RAM you don't need a 20gig swap. No need to create a swap partition at all really as the installer will create a swapfile in root for you. And unless you intend to "hibernate" Ubuntu (suspend to disk), you don't need more than a gig or two of swapfile. If you will be hibernating then you'll need a 16gig swapfile. I have 32gigs and no swapfile at all as I have plenty of RAM to run everything I need without running out of memory. YMMV.