I've been trying to boot up my Win7 USB stick into EFI mode as the disk I want to install it on, is GPT. I have tried to modify the installation media (including copy bootmgr.efi, bootx64.efi and such), but I keep getting a winload.efi file is missing error, which is a bit weird because setup disks aren't supposed to have a system32 folder containing a winload.efi file.
My Motherboard certainly supports EFI boot. When inserting my flash drive, I get two options for boot, one bios and one UEFI. Also, I've installed Win8.1 on a GPT disk, as well as a previous win7 install, which I seem to have forgotten how I managed to make it work.
I've tried going through a lot of topics, and the entire idea about EFI boot using files still remains very foggy in my head.
So I w would really appreciate it if I get a clear idea of how EFI boot works in this case(more from the perspective of what files are needed):
- What are the files needed for EFI boot for a windows setup USB?
- What files have been renamed but are actually similar files? (such as
bootmfgw.efiandbootx64.efi)
And the purpose of the other folders/files(correct me if I'm wrong):
sources: files Windows needs during installation, including the .wim file.boot: BIOS installation boot filessupport: additional toolsautorun.inf,setup.exe: Files needed for Autorun
My motherboard also has an option to Launch EFI shell from file system device, requiring it to have a shellx64.efi file. Is this the same as the bootmgr.efi file? Will copying/renaming it work?
2 Answers
prepare usb stick with rufus and point it to the windows iso, selecting gpt and fat32. rufus will prepare and populate the efi/ directory on the stick, so you can install windows 7 in efi mode.
Pingers
5After a bit of tampering with additional ISOs, I've realized that you can just replace the \sources\install.wim file on a Win 8/8.1/10 bootdisk with the one from Win7 to make it work.
- Just get a Win8/8.1/10 ISO
- Open it using an ISO-explorer (like UltraISO)
- Replace \sources\install.wim with that from the Win7 ISO/DVD
- Save as a new ISO, and/or burn it into the installation DVD or on a USB/external HDD active Fat32 partition.
The installation UI will be of the bootdisk's Win version, but it will certainly install Windows7.
Conclusion: Perhaps, (my) Windows 7 efi boot files are just... broken.