I had Linux Mint on dualboot, but I was having problems with the audio, so I deleted the partition using disk manager on windows 10, and was going to install Debian, but when I try to boot Debian from the usb, it goes to GRUB and I am unable to get past this. I tried many solutions on various forums and none of them have removed this obstacle. Anyone got any ideas?
If your computer supports UEFI boot, you should be able to boot directly from the flash drive (reference your motherboard's keyboard shortcuts for the exact boot key). Otherwise, you'll need a direct-write utility to write the ISO to the flash drive. Unetbootin is old software and not necessary when you have a bootable ISO (most are these days).
As @jdwolf already commented...
You may actually be booting from USB after all. If the system is booting in UEFI mode, there should be an UEFI bootloader at
\EFI\boot\bootx64.efi on the USB stick. On Linux installation media, this UEFI bootloader is often an UEFI version of GRUB.
unetbootin changed the layout of the boot files without also adjusting the configuration of the UEFI bootloader (which might be found at
\EFI\boot\grub.cfg), then your boot attempt from the USB media might end up with an UEFI GRUB with no valid configuration.
It is also possible that your UEFI implementation may be buggy. Some UEFI versions of GRUB were quite sensitive to UEFI implementation details - I think this has been improving lately, as the GRUB developers receive bug reports and other experience on various UEFI implementations.
With modern distributions,
unetbootin and similar tools could be unnecessary for preparing an installation USB media: many installation ISOs come now prepared with
isohybrid (see here) or similar tools so that you can simply write the ISO to the USB media using
dd or a similar tool and have it just work. This way both the legacy BIOS and UEFI bootloaders on the installation media should be using the configuration that the distribution maintainers have actually tested, rather than a configuration built by
unetbootin using heuristics.
As a last resort you can try to enable "legacy boot" option if supported by you BIOS.
In my previous experience (hp envy 15 amd apu), the bootable flash drive (gentoo x86_64) required this option in order to be detected by the bios.