4-5 days ago when I was trying to install Ubuntu in my ACER ASPIRE 3 (A315-31-C0A7 model number N17Q2) but it was error saying media file corrupted and now its showing no bootable device I also tried with another bootable pendrive installed Ubuntu bit it's showing default bootable device missing. I tried everything I got from online but nothing works. My hdd is shown in boot information menu. But it's not showing in boot menu. Please help I am desperate I bought this laptop from Flipkart on 26 May 2018.