Hello, I would like to know how to install Windows 8 from a hard drive partition, so that is much faster than installing from a USB ... I've seen guides on how to do, how bad MBR, and I want to know how install W8 from a partition GPT / UEFI.
If you extract it on a partition on a second HDD and make that partition active you should be able to boot it by selecting it in the bios boot menu I think, but I doubt that it will be faster vs USB.
You need a partition on the HDD that is FAT32, then you'd just toss the Windows files from the install media over to it as-is. Then, ideally, you'd reboot, and be able to choose that partition as UEFI boot (it should detect the .efi file). It depends mostly on your motherboard's UEFI implementation. My old laptop only detected efi files if they were in a "specific" folder structure, and named specifically (I think it was /boot/efi/bootx64.eft). Generally speaking though, if you want a cleaner install, I'd probably just recommend using a flash drive still. Install shouldn't take longer than 20 mins over a USB 2.0 drive.
I can confirm that if you somehow boot the proper boot.wim (via usb, adding a bcd entry to an existing one, from an iso, cd, etc) and then run x:\sources\setup.exe from the booted wim it will scan the root of all HDDs, USBs, cds, etc until it finds an install.wim in sources. As long as it is in the root of a drive and in the sources directory you have install.wim, a boot.wim, and setup.exe (only 3 files needed) it should work. And for the record, IT IS faster via an internal HDD. I've used this method for years for my personal wim setup files.
If you launch setup.exe from root or sources folder, it ends up installing a windows MBR, I think OP wanted to install windows EFI.