So I fixed my previous question by getting a valid UEFI installer disk and completely formatting my SSD. I installed Windows 10 on half of it and installed Linux Mint 17.3 afterwards following this tutorial:
Everything was awesome and good until I restarted, where Windows 10 looked like this:
It turns out that something is wrong with the way GRUB uses the video card before the OS is on, because I can still actually open google chrome and similar things despite the very weird graphics.
Also, after I turned off the computer to try and fix the glitch, GRUB was no longer visible and it booted directly to Windows 10
How can I fix this?
If you have installed Linux side by side with windows in UEFI you might or might not have done the following actions(which you should or Linux did it for you):
- Disable compatibility CSM module.
- Disable Secure boot
- Create a new EFI entry
- Insert GRUB in that entry
- Keep windows entry and leave the dual boot option in GRUB
If you haven’t done the 2 first actions prior to installation then leave it that way. Although it might cause compatibility issues.
Remember that by default, both boot entries are available in the EFI, which you could select by pressing F8 or F10 during POST or change the BIOS settings to select it(the entries should be like /dev/sda1 Windows Boot Manager and (/dev/sda2 & /dev/sda3) Linux), you can completely skip grub by selecting windows boot manager in boot time.
You can also completely disable GRUB later if you prefer this boot selection of UEFI(which also fixes some weird issues.)
P.S: If you have accidentally removed your Linux boot entry, you have to reinstall it, as the installer will create new entry every time it detects windows boot manager, and if you have accidentally removed your windows boot manager, you have to repair it with your windows installation disk or USB.
There are also some tools available to modify your EFI, but those tools are risky, considering that a faulty EFI could brick your board. so don’t use them unless you know what are you doing.