UEFI has feature called safe boot which adds a extra layer of security to the loader and it prevents booting from external sources like bootable USB Drive or CD. I ran into the same problem when I changed from Windows 10 (due to it's current flaw -the increased internet usage through background apps and system updates) to windows 7.Īlthough it is marked solved, I still have taken the time to add my solution hoping to help future readers of this thread. Therefore installing windows 7 and lower OS that is BIOS Based and uses MBR disk partition takes some proper configuration to be successful. Windows 8 and higher OS uses UEFI mode and has GPT Disk Partition type by default. Don't choose removable, choose hard u will see your hard and USB stick 1) Make sure that your USB bootable shows on a working computer before trying the new BIOSĢ) CSM or Legacy selection are for booting Windows 7, I think, and the UEFI selection is for Windows 8.ģ) when u start press F10/F11(or whatever key) for boot options and if u see categories as removable, hard, CD and etc.

Lenovo windows 7