Win 10 Install force use of EFI, Win 7 forces use of MBR, can't dual boot

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Peace Man

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Hello to any and all support,

I have installed a 480GB SSD that Win 10 Ultimate would not use as MBR but did accept as GPT with AHCI. Then Win 7 Ultimate would not use space on SSD because of EFI so I put the Win 7 on a 1TB HDD and then tried to dual boot from either but easyBCD would not connect. I did load the Win 7 from Win 10 but it then refused to see the presence of the SSD to go to the correct BCD to allow selection.

Thanks for any help, have tried regedit and lots of stuff but no solution so far.

Dave
 
Dear Terry60,

I have Win 7 and 10 running on my 64 bit main laptop w SSD as well as my secondary newer laptop with no problem, it has GPT and UEFI. I have upgraded that unit to Win 10. On my 3rd and much older Laptop system, I have Vista and 10 running. On my power desktop system, Even in a new test today, using all 64Bit OS', the Win 7 Pro direct from MS said it must go on a MBR disk and the Win 10 pro on a stick, direct from Best Buy, said it had to go on a GPT disk. I had used Win 10 on several MBR systems when I was first in the MS Insider test group. Win 10 Insider went everywhere. MS has changed the game with the production units.

On your reference to the MS data on such thing, please allow me to thank you dearly for that link. :wink: Below is my copying of the data and my take on it, please feel free to point out any questions or better answers:
"Question 1: Can Windows 7, Windows Vista, and Windows Server 2008 read, write, and boot from GPT disks?
Answer 2: Yes, all versions can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on UEFI-based systems.

Question 2: What about mixing and matching GPT and MBR disks on the same system?
Answer 2: GPT and MBR disks can be mixed on systems that support GPT, as described earlier. However, you must be aware of the following restrictions:
Systems that support UEFI require that boot partition* must reside on a GPT disk. Other hard disks can be either MBR or GPT.
Both MBR and GPT disks can be present in a single dynamic disk group. Volume sets can span both MBR and GPT disks."

The above is from MS website that you sent to me. The statement after the asterisk (*)is not true, I have been trying to use a 64 bit version of Win 7 pro on a hybrid EFI MB and it says that the 64Bit Windows 7 must go on an MBR disk. It loads everything and then at the very end, it aborts. I have other hard disks for that system that I had loaded with MBR and GPT, both had Win 7 and Beta 10. I did add memory 8GB +24GB and a 4TB HDD to the mix as well as the 480 SSD. I am including a screenshot of the layout of a disk that was working.

Any assistance from anyone is appreciated.
 

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That statement is ambiguous rather than untrue.
The boot partition must be on a GPT disk to boot in UEFI mode.
When I installed the W10 trial, I put it "clean" on a spare MBR HDD partition, and put that top of the boot priority temporarily to be able to multi-boot my W7/8.1 SSD from the W10 BCD.
It was happy to boot both GPT partitions on the SSD from the MBR-located BCD, but it did so in compatibility mode. i.e the BCD loaded winload.exe to boot each GPT system instead of winload.efi as used from W8.1's BCD on the SSD.
Winload.efi cannot be used to boot a system from an MBR drive, but you can do the reverse.
Keep playing with the setup options to get past the "W7 must go on MBR" hurdle.
That's your problem (and it's not true), but something about the way you're doing it must be incompatible.
It's a long time ago since I built this UEFI GPT SSD PC, but I do recall having several false starts with getting the OSs where I'd allocated space for them.
Unfortunately now, I don't remember exactly what the problem was or how I solved it, but reading those FAQs carefully (in detail) was certainly one of the things that helped.
Do a web-search for UEFI GPT and look at all the Microsoft URLs you find.
 
Hello to My Friend Terry60,

Thanks for the good and speedy reply. I have a few additional bits of information to add to the chat. I have the good fortune of a number of 'tech experts' at a giant computing mall who do work with me for nurturing our good friendships. 4 of them worked over a period of 6 hours in trying to help with this install. One senior expert on installation would have charged me but, in the end, he was unable to get Win 10 Entrp to install so I paid nothing. I then turned to my 50 years in computers to install Win 10 Enterp on the SSD with the combination of AHCI and EFI enabled. I also had to accept that Win 7 Premium, Pro and Ultimate/Enterp were not going to go on a GPT, be it SSD or HDD, as I tried them all. Yes, we are hitting a gnat with an atomic bomb. ha ha ha

It may be useful to know the hardware that we are basing all these tests and software on:

At the heart is an older Gigabyte GA880GA-UD3H Hybrid MB dual BIOS using onboard graphics, 32GB DDR3 RAM, AMD Phenom II with 6 cores, 480GB GPT SSD, 1TB Toshiba MBR HDD, WD 4TB GPT HDD, 2 Seagate 1TB SSHD(1 GPT & 1 MBR, both used previously with Win Vista, 7 and beta 10 all working). The MB allows you to go in IDE, IDE & RAID, Auto so usually I select Auto. Also a version of AHCI is on board and I know that HD's above 3TB require EFI to access the added space.

Please read on.

My Friend Terry60 wrote: "That statement is ambiguous rather than untrue."
The actual statements at Microsoft states : " Systems that 'support' UEFI 'require' that boot partition 'must reside' on a GPT disk. Other hard disks can be either MBR or GPT."
Microsoft also states above the previous statement: "Can Windows 7, Windows Vista, and Windows Server 2008 read, write, and boot from GPT disks?
Yes, all versions can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on UEFI-based systems."

DAVID REPLIES: My system does support UEFI however, my tests using a GPT formatted SDD with a Win 7 Pro 64 Bit, bought directly from MS Store, were rejected by the Win 7 installation program. The installation program gave the detail that the disk was GPT as the reason for rejection(MS Has been notified.). MBR formatted disks were accepted and are currently being used. Many of the massive number of possible combinations were tried just to get Win 10 to fully install on a GPT formatted SSD and I finally hit the combo of EFI, AHCI and GPT that worked.

My Friend Terry60 wrote: "The boot partition must be on a GPT disk to boot in UEFI mode.
When I installed the W10 trial, I put it "clean" on a spare MBR HDD partition, and put that top of the boot priority temporarily to be able to multi-boot my W7/8.1 SSD from the W10 BCD."

DAVID REPLIES: Reading this carefully and remembering my own experience back when doing The same without Win 8, 8.1 but using an SSD, I was using only HDD's, as the layout of my disk shows, even Linux worked good on MBR but some Linux would not work on GPT. I could multi-boot when using 1 HDD for my many OS' but never across HDD's.

My Friend Terry60 wrote: "It was happy to boot both GPT partitions on the SSD from the MBR-located BCD, but it did so in compatibility mode. i.e the BCD loaded winload.exe to boot each GPT system instead of winload.efi as used from W8.1's BCD on the SSD. (DAVID ASKS: What was the physicals of the drives you were using, 1 or 2 drives? Where was/which drive contained the " MBR-located BCD"? We know that GPT partitions cannot be on MBR disks.)
Winload.efi cannot be used to boot a system from an MBR drive, but you can do the reverse. (DAVID QUESTION: Do you mean by "the reverse" that "Winload.exe "can" be used to boot an EFI system?)

DAVID REPLIES: It reads like you are correct on this, I have been trying to use winload.exe exclusively to boot across 2 different HDD/SDD drives when using EasyBCD. It stands to reason, EFI is going to look for the other reserved areas for info on the location of info on an EFI(larger capacity hard drive) system. However, I have to state that a "clean" Windows 7 Pro (purchased directly from MS) just simply would not go on a "clean" partition on a GPT SSD behind Win 10 Enterprise. I have a spare 120GB SSD that I am going to put strip out all the HDD's and the other SSD and try to put Win 7 on it as a Final method to make sure that the 2 cannot coexist on a single small system.

My Friend Terry60 wrote: "Keep playing with the setup options to get past the "W7 must go on MBR" hurdle.
That's your problem (and it's not true), but something about the way you're doing it must be incompatible.
It's a long time ago since I built this UEFI GPT SSD PC, but I do recall having several false starts with getting the OSs where I'd allocated space for them.
Unfortunately now, I don't remember exactly what the problem was or how I solved it, but reading those FAQs carefully (in detail) was certainly one of the things that helped.

DAVID REPLIES: While I am not quite sure I agree, it stands to reason that something is clicking with my system to say it is fully UEFI and Win 7 is saying I play only MBR in those circumstances. Using a decimated system to reduce things to their essential cores should get me to a replicable scenario of what does and does not work. Having been at a state with a "clean" 175GB partition on a GPT SSD, Win 7 installed but at the tail end, just read it all back out on one time and then again, Win 7 install program read the system and stated that the disk was not acceptable as it was GPT, ergo, shut down without starting. I now have 2 OS drives; 1 GPT SSD and 1 MBR HDD, that cannot boot to the OS that resides on the other. The Bios must specify which disk to use to start the boot process. I have tried to be extra specific in this as I do want to take ambiguity out of the calculations.

Thanks much and hope that all this does not snow you under, there is a light at the end of the tunnel --- or is that a freight train coming full on? Ha ha ha
David
 
Are you trying to install W7 after W10 ?
That may be the problem.
The "natural" order, i.e. chronological order of the release dates of the Windows versions, is necessary for the Windows setup program to function in the way it was designed.
Windows bootmgr provided with each new OS is fully backward compatible with all previously released versions of WIndows.
It will see the pre-existing BCD and bootmgr (on the "active" partition for MBR, in the efi system partition for UEFI GPT) and replace the old version of bootmgr with its own and add itself into the pre-existing BCD. This new bootmgr will load any of the older levels of winload.exe without problem.
The older version of bootmgr is incapable of loading a newer winload (it will fail with "invalid digital signature", thinking that the module is a pirate version).
In the past (MBR days), installing Windows in the "wrong" order would work, but as soon as one tried booting the newer system the inv-dig-sig problem would occur.
This was fixable by doing a startup repair from the newer system's DVD or by dragging the newer bootmgr across to replace the older.
It could possibly be the case, that with UEFI, the Windows setup has got a bit more clever to prevent you from trying to back-level the boot files.
Try formatting your SSD with the spaces for the two systems, then installing W7.
If it's happy to go on the GPT SSD then that's the solution.
W10 will install subsequently and automatically dual-boot itself.
 
Terry60, it was such a disaster trying to get W10 put on that once that was solved, I just assumed that my old versions of Win 7 would be a breeze, Not So! I am going to use a small 120 GB SSD to load Win 7 Pro in the AM with GPT and with no other disks in the system, nothing to complicate it. If that works, I will move on to adding Win 10 Pro onto that SSD system in its own partition. Should that to also work, I will upgrade both OS's to the top of the Win chain and onto the 480GB SSD, have to get a 960 from the US soon, Over here they are still very high priced in comparison.

I will share that I think that the big 4TB GPT disk is forcing the Bios to opt for UEFI and that is a hanging chad. Win 7 really should be able to load on an empty partition on a GPT drive and then boot from it, regardless. It would not even boot to an empty GPT disk.

Best to you,
David
 
Hello to all, Especially my good friend Terry60,

SOP, DD or Same Old Problem, Different Day. I have researched this very hard, I know that many others have accomplished the task of getting Windows 7 installed onto GPT disks and being able to boot from those disks. I know that the subscribers in the affluent business world will eventually be going to Windows 10 because MS is going to pretty much let 7 die. I am also aware that many lesser developed nations and some businesses for myriad reasons are going to drag to the end with old OS'.

I still seek and welcome any and all info on a quick and easy convert for the Windows 7 OS from MBR to GPT . I have tried so many different ways to get Win 7 onto GPT; MiniTools Partition Master has a converter for the job that did not work, every attempt to run Win 7 install onto GPT failed, tried using Diskpart from MS and that is a can of worms (but now that I have the extra HD's with Win 7, I am going to revisit that.) I do really like Win 7 and not too happy yet with Win 10. I am waiting for the upgrade next month for MS to bring out the Win 10 update with active stylus pen software for non touch systems.

I have resolved to put Win 7 on an SSHD by Seagate or a small 120GB SSD that I have that is not being used. The main system will be Win 10 on a 480GB SSD, with back up Win 10's on 2 other SSHD's along with 2 Win 7's with a WD 8TB My Cloud Mirror to back up things externally and a WD 4TB to back up things internally for my main unit. My laptops and tablets will also use the My Clouds. I had to get rid of the Samsung, Clarus, Seagate back up as it was locking up my main laptop.
 
Hello to All, especially Terry60,
The name of my tune tonight is "O Happy Day!" as I finished inventorying all my hard drives and SSD's and the last disk that I ran Partition Wizard on was formatted GPT and had a couple of Win 7 OS' loaded on it according to PW. It turned out that 1 was not but, thank goodness, the other was good so I am now a happy camper, all systems are go. As soon as the 1TB SSD's get reasonably priced here, I will move Windows 10 and 7 to one and move my main libraries there as well. Here in this SE Asian country, good Internet is NOT to be had and there is no such thing as unlimited use. My mouth waters at the prices of good SSD's and monitors at Newegg and Best Buy. I will be visiting the US soon so I will be buying to my heart's content or as much as my wallet will allow.

Thank you Terry60 for all your assistance.

Best to all,
David
 
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