As I said in this post
I won’t have time until the weekend, but I have another Windows 8 Pro Upgrade I bought last week while the price was still right, and my laptop is EFI capable. I’ll try some combinations, take some notes, and post the aftermath.
After making fresh images of my partitions/logical drives on my laptop, I tried to enable EFI. After clicking that radio button in BIOS, I immediately got an error message “no boot device”. My drive is formatted MBR, and EFI only works with GPT. Conundrum #1.
I put my Dell Windows 7 Pro SP1 x64 OEM installation disk in the drive (Dell ships a full install disk with the laptop if requested, at no extra charge), shut down the laptop, and then started it again, and got back into BIOS. This time when I clicked the EFI radio button, my CD/DVD drive appeared as a device, and I put a check in the box, clicked apply, and Exit. The laptop booted into the Windows 7 Pro setup. When there is no disk in the CD/DVD drive, it is not an eligible EFI boot device – must have media. When setup had progressed to the point of selecting a partition for installation, I used Shift +F10 to get a command prompt, then typed in “diskpart”.
Using diskpart, I cleaned my MBR drive, then converted it to GPT, created a 102MB EFI partition and a 32MB MSR partition. From what I’ve read, those two are necessary for booting from a GPT drive. Next I created a couple of 60GB partitions, and selected the first of those to install Windows 7 Pro.
That went well. I didn’t bother with any personalization, since I intended to format it again to install Windows 8. I had previously prepared a thumb drive for booting and installing Windows 8. So after Windows 7 Pro was running, I shut down, plugged in my USB drive, and selected USB under the list of LEGACY BOOT Devices. Clicked Apply and exit, booted into the Windows 8 setup, pointed to the 60GB partition holding Windows 7 Pro, and it refused. It couldn’t install in a GPT partition. Conundrum #2.
So I rebooted, and got back in BIOS and Boot Sequence. Paying a bit more attention, under UEFI BOOT was listed “Windows Boot Manager”, and below that, “UEFI: INT13(,0x80)”. It was listed there before, as well, but it doesn’t say USB, and USB was listed under LEGACY BOOT. But I selected it, anyway, and booted, once again into the Windows 8 setup. This time when I pointed at the 60GB partition containing Windows 7 Pro, got no complaints, clicked on Format, and only got the usual warning about losing everything on the partition.
And Windows 8 Pro Upgrade did the format, installed, and activated without a hitch. I even applied for my free Media Center Product Key and got the 72 hour email promise. The first time I installed Windows 8 on my laptop, EFI was disabled, and during the inspection by the upgrade advisor, I was told that my system was not capable of Secure Boot. I didn’t run the advisor this time, just the installation, but I didn’t see anything about Secure Boot. My guess is that it is enabled, but I haven’t examined all the nooks and crannies of the BIOS yet to find it now that Windows 8 Pro Upgrade is installed.