I am installing Ubuntu 12.10 on an acer 5315 laptop. I have burned an image of the ISO on a DVD and when the disk boots everything looks like it is going according to plan. I choose the option to replace my windows OS and delete all data and files and the install begins. I pass the various screens while the files are being copied but then at some stage during the copying process my laptop just switches itself off with no warning. I have tried 3 times now and it always switches off at completely different times during the installation. Any ideas? the DVD is brand new and seems perfect.