I have a 2011 Dell XPS that I have been trying to load Linux Mint onto (it was running Windows 10). I use a USB thumb drive and flash a copy of Mint .ISO from this Linux site and can operate Mint on the PC from the USB. However after loading the software onto the PC, rebooting and removing the USB, my PC now just get "Operation System not found" on boot up. How to I fix this?

