I tried to install ubuntu from a usb flash drive and replace windows that was already there. The installation seemed almost complete when an error occured telling me that I should reboot the computer. I did that, and then a screen saying "No bootable image found, notebook will be shutdown" appeared. I tried to restart it and open BIOS to install the os again, but BIOS won't open. Is there something else I can do? I found somewhere that removing the CMOS battery for 20 minutes could help. But I don't want to mess with hardware until it's my last option. Thanks in advance for any advice