Jan 31, 2019 - If you are using Windows 7 64-bit, Windows 8/8.1, or Windows 10, you can change Legacy to UEFI mode to get better performance and disk.
It does look like you have had some fun modifying the original Windows partitions. I don't see any active partitions, so you don't seem to have any Legacy installs.
Can we assume the current C: partition, 199.76 GB is your Windows 10 install and the D: 200 GB is the Windows 7 install?
When you boot the system, do you see a GUI boot menu or no boot menu at all? Are you sure you installed Windows 10 to the correct partition and did not overwrite the Windows 7 install?
You could try booting to the Windows 10 Install media and running a command from the Command prompt. It might pick up the Windows 7 Boot and add it to your menu. The utility bootrec.exe can be used to Rebuild the BCD Store and hopefully pick up the Windows 7 options.
bootrec /RebuildBCD
https://support.microsoft.com/en-us/kb/927392/
Is there any way you could provide a copy of your BCD store. Since you can't attach files here, you would need to provide a link to some storage location, such as OneDrive for us to have access.
From an Administrative Command prompt:
bcdedit /enum all > %userprofile%Desktopbcdtext.txt
Then zip and post somewhere. If you don't want to do this, just type bcdedit and see if it shows a Windows 7 listing.
If you have the ability, it is always best to remove any drives not directly involved in installing an OS. As you have seen, it can lead to confusion as to where certain components are positioned. Placing drives on different SATA ports can also effect how the partition structure is seen during boot.
I own Acer M5 recently and it comes with 64-bit Windows 8. I need it to run Windows 7 x86. I changed the BIOS setting to boot under Legacy BOOT instead of UEFI mode.
I created my bootable USB using UltraISO. But when I select a partition it said 'windows cannot be installed on this disk. The selected disk is of the GPT partition style'.
A quick google search yeidls http://forum.acronis.com/forum/40223 and it seems like we can't run 32-bit. If I delete every partition will it work?Any alternative?
Thanks.
CppLearnerCppLearner40833 gold badges77 silver badges1919 bronze badges
4 Answers
Your computer ships with a 64-bit EFI implementation. Such an EFI can boot only 64-bit OSes in EFI mode. Thus, to boot a 32-bit version of Windows, you must boot it in BIOS mode. This requires converting the partition table (not just a single partition; the entire partition table) from GUID Partition Table (GPT) form to Master Boot Record (MBR) form, since Microsoft has decided that it won't support booting in BIOS mode from GPT disks. Most disk partitioning tools can make this conversion in a destructive way (wiping out everything that's already on the disk), and a few can do so non-destructively. My own GPT fdisk (
gdisk
) is one of the latter. Note that MBR partitioning goes by a number of other names, such as 'MS-DOS partitions' or 'BIOS partitions.' Thus, you might need to look for the right name, depending on what tool you use.Note that even if you convert the partition table non-destructively, your existing Windows 8 will probably stop booting. (I haven't tried such a conversion myself, so I'm not 100% positive of that.) Essentially, you must boot all your Windows OSes in one mode (BIOS vs. EFI), at least if they're installed on one disk. If you want to dual-boot, this could be a problem, since given your stated goal, you may have to re-install Windows 8 in BIOS mode. This in turn will require access to a retail version of Windows 8, since the OEM restore tools will probably only restore in EFI mode.
This might be a bit easier if you're willing to run the 64-bit version of Windows 7. You could then install it in EFI mode rather than in BIOS mode, which would not require any partition table conversions and would enable dual-booting, if that's something you want to do.
Rod SmithRod Smith
17.6k22 gold badges2121 silver badges4444 bronze badges
I know this is way past the relevant time-frame, but let's set some things straight for the record.
- @RodSmith is right in that tying BIOS firmware to MBR partitioned boot disk is a limitation introduced by Windows, not something inherent to BIOS/MBR. All modern versions of Fedora and Ubuntu work fine, in both x32 and x64 versions, with BIOS booting on GPT systems.
- While I agree with @RodSmith that Windows 8 will stop booting on conversion from GPT to MBR, it should not be necessary to reinstall. A bootable DVD of Windows installation contains all the tools to fix it up, either automatically, or failing that, manually. Basically it involves writing MBR (using
bootrec
orbootsect
), designating one system reserved partition (the erstwhile EFI System Partition will do), Volume Boot record (again usingbootrec
orbootsect
), and then reintroducingbootmgr
andBCD
(usingbcdboot
). About half an hour overall. - It is not strictly true that Windows cannot boot from GPT on a BIOS system. Here is my technique for doing the 'impossible' :
If you even have a small spare drive, you can boot Windows(either 32 or 64 bit) from GPT on BIOS. A floppy will do.
Boot into the Windows install/repair disc.
Create the system drive on the small disk/floppy, and use
bcdboot
to put your boot files on the the newly created drive on the small disk. Add a bootsector with bootsect
. Change the {bootmgr}
device
to boot
. Boot from small disk.Steps are detailed here.
Community♦
Milind RMilind R
Faced a similar issue recently and this is what I did
Disabled UEFI. Switched to Legacy
During Windows 7 32 bit setup chose custom installation and deleted all existing partitions. Created a new partition from the unallocated space and windows setup allowed me to use that partition to install windows
abelabel37733 gold badges99 silver badges2525 bronze badges
The UEFI (Unified Extensible Firmware Interface) only support 64-bit Windows and GPT disk. You can't boot an 32-bit OS with a MBR disk on it. You need to install 64-bit Windows and GPT disk to boot in UEFI. For 32-bit and MBR, you must boot on Legacy mode.
Ken NgKen Ng
protected by Community♦May 26 at 11:38
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