I am trying to install Windows 7 Professional (64-bit edition) on a Lenovo Y50 computer with UEFI and a GPT-formatted hard disk.
This computer is currently running Windows 8.1, which boots correctly. Its hybrid hard disk is formatted GPT. I would also like to keep the disk GPT-formatted and UEFI mode enabled The PC has no CD/DVD drive, so I must use a USB drive as the installation/boot media. I used the utility Rufus (options FAT32 and GPT for UEFI selected) and an ISO of the installation DVD to create the installation media on another Windows 8.1 machine. I then turned off secure boot on my target PC and booted the USB. I got past the "loading files" screen and saw the familiar Windows 7 "points of light" boot animation with the words "Starting Windows". At some point, however, the animation and - apparently - the rest of the system froze completely. I was forced to use the power button to turn it off.
Things I have tried:
- Trying the whole thing again
- Waiting at the frozen "Starting Windows" screen
- Using the Windows 7 USB/DVD download tool to make the bootable USB drive
- Mounting the ISO and copying all files to a new FAT32 volume on the flash drive
- Switching hard disk from AHCI to "Compatible" mode in the UEFI settings
- Switching off the nVidia graphics card in UEFI
Needless to say, none of those worked. A few of them made my system not recognize the thumb drive as bootable at all. The others led to the same hang I experienced the first time.
Things I have NOT tried:
- Using Compatible/legacy/BIOS mode: I want to use UEFI to boot my system.
- Using a DVD or CD to boot the system: This PC does not have a CD/DVD drive, and I do not have any external drives available at the moment.