Manjaro On MSI GS60

I installed and ran Ubuntu on the laptop until it's novelty wore off and now I want Manjaro on it.

I burnt the ISO with unetbootin and got it to boot in legacy mode. After the install completed I rebooted into the hard disk and all I get is grub rescue: unknown filesystem. I try to reboot into the usb and now the usb won't boot. The Windows 8.1 partition still is working fine.

Any help would be great.

You have a few options.

1. Find the partition with grub recovery and boot into Manjaro.

This webpage shows the basics -->  Linky

2. Chroot from any linux live disk/media and recheck grub with a few extra flags if a simple install won't work.

Arch wiki --> Linky

eg; sudo grub-install --recheck --disk-module=native /dev/sdx

don't foget the grub config tool   grub-mkconfig -o /boot/grub/grub.cfg

3. Not recommended but use BCDBoot in windows.