Hi. I'm not sure if this belongs in this forum or not but I have a Lenovo G580. It came with Windows 8 and I downgraded it to Windows 7. I had to make obvious BIOS changes in order for this to happen because they were default to Windows 8. The issue I am having is when the battery dies or is removed (power discharged) the BIOS resets making Windows 7 boot impossible unless making those necessary changes. I have changed the CMOS battery and the BIOS is updated to the latest version. Lenovo support is no help so I am at a loss.