Boot Windows 7/8 from GPT on BIOS system : No hybrid MBRs or DUET!

cuisinart · 23 Aug 2014

Oh, I wasn't talking about this forum. It's great. cheers.

milindsmart · 24 Aug 2014

gregrocker said:

We offer Best Practices (many of which were developed here) that have made this the top tech forums in web history, serving millions of average consumers. We are not about to put any consumer through the hoops you've just jumped unless they specifically request it, especially for 32 bit which doesn't even address more than 3.5 gb RAM so would only be needed in the rarest cases, if then.

I admire the persistence and ingenuity in this thread but it is anomalous and may never be requested again.

I see no reason to shield users (why would you refer to them as consumers) from jumping through "hoops" (as you call them) without their express request... Kind of the opposite policy stated above. Also, both 32- & 64-bit windows need the same treatment in this context.
Loads of people have > 2TB harddrives, and not many have UEFI machines. Very logically there arises a mainstream need to use GPT on BIOS machines. Once there is a need, many many people will be prepared to do whatever it takes to get it to work.... and this is not like a treacherous trek to Mount Doom under the searing gaze of Sauron. It's still only a bunch of commands and software.

Why would you want to consider users so incapable?

gregrocker said:

Meanwhile every day we help more consumers sort the UEFI firmware BIOS settings which is different on every model, doing the diligent support that the mobo and PC maker's don't begin to provide.

TBH I consider UEFI an unneeded layer that greatly complicates installation and Repair protocols that worked just fine before and now must be completely reworked differently for every mobo. As with RAID we only see problems with it here, and rarely see a single positive thing mentioned except from consumers.

This is more because of unstandard ways of entering the firmware than anything else, which, I agree is the responsibility of the PC/Mobo makers. But UEFI was in the offing for a decade or more, and it has come slowly but surely... Just because we've spent 30 years with the BIOS and everyone has got used to it doesn't mean we should use such a kludge forever. My reading rarely shows big problems with the actual functioning of UEFI itself, but my experience is not exhaustive, to say the least.

PHubb · 05 Sep 2014

Hello All; There are many ways to accomplish this, but I want to thank Milindsmart for suggesting the concept and idea. I am now dual booting Win 7 and Win 8.1 Pro on a GPT 3.4 TB array on an old P55 BIOS MBR system. Basically, as outlined, you need 2 separate disks- either 2 hard drives or USB stick and HDD as suggested. I tried it with the USB stick first - worked great. Just copy a Windows 7/8 hidden BOOTmgr file into the root of the stick. Then copy the hidden Boot folder into same. Now you need to point (edit) your BCD file (in the USB stick's Boot folder) to your Windows installation(s) on the GPT disk. The old MBR BIOS reads the boot info from the USB stick, presents a boot menu (in dual boot configurations) and you select which OS on the GPT disk to boot to and all is good. To edit the BCD (boot configuration data), I used EasyBCD 2.2 It's a graphical (and much easier) BCD editor. To get my system to dual boot both Win 7 and Win 8.1, I had to copy over the updated Windows 8 BOOTmgr file into the root of the USB stick, otherwise, 8 won't load. The 7 BOOTmgr doesn't correctly recognize the newer Win 8 OS while the 8 BOOTmgr will recognize and boot older windows OS. Now to transfer all of this over to a second hard drive in the system so you don't have to keep using the USB stick to boot to your large GPT disk, although truthfully there is no noticeable performance hit booting from the USB stick). After the OS loads, you can actually eject the USB stick and use it normally to carry with you and transfer data between computers. Problem is - don't loose it! or have another computer load a virus onto it which will corrupt your boot process. A cleaner, more stable (and safer) solution is with a second HDD that is permanently installed in the computer.
1st: The second drive has to be formatted in the old MBR partitioning scheme (which it most likely already is if in an older computer). It can be any old drive of any size. If you have an old working drive laying around, use it. If you already have a second data HDD, use it.
2nd: If there are already partitions and data on the drive, you will have to do some resizing and moving of partitions. Use any of the excellent free Partitioning software out there. I use EaseUS PM. You can also use the built in Windows or
command line DiskPart. Basically, you want to free up about 100mgs of free space (unallocated) at the very beginning of the drive. This will be where the MBR boot files will eventually reside. Now create partition in and format that 100 mgs free space you created at the beginning of the HDD. You can name it System Reserved and set the 0x7 flag (DiskPart) so the BIOS will know to boot from it or you can use EasyBCD to deploy (copy) MBR to the new partition. Once the new partition is bootable, you will need to edit the BCD to point it to the Windows installation on your GPT disk. EasyBCD works great for that as well. Don't forget that for a partition to be bootable, it has to be set as the ACTIVE partition. If you use EasyBCD to Install an MBR in a partition, it will also mark it as ACTIVE. If not, you can use Windows Disk Management, DiskPart, or other partitioning software to set the partition as ACTIVE.
Let's take a hypothetical, but I think relatively common situation. You have one older BIOS MBR based computer that boots Win 7 (64 bit). You have just bought a new 3 TB HDD. Maybe your older HDD with Win 7 on it is getting slow or is old and might be failing. You want migrate your OS over to the new 3 TB HDD you just bought, but also want to use all of the space and not be limited to 2.2 TBs by the MBR partition scheme. This means formatting the disk as GPT partition scheme. Problem is, older MBR BIOS based hardware won't boot to a GPT disk. Create the GPT disk, then migrate your current OS over to it, using several possible programs (EaseUS PM has a neat 'migrate OS to HDD/SSD' feature). You can also make an image of your OS(s) and restore it to the new GPT disk. Macrium Reflect will allow an MBR image to be restored to a new GPT disk.
Before migrating/imaging your OS, I suggest a thorough clean-up of it using Disk Cleanup or other. I also suggest installing all the latest Windows/virus updates. Uninstall any programs you don't use. If on a HDD, defrag it. Not necessary if on a SSD.

The point is you need to get/copy your Windows onto the GPT disk in a DATA partition. I imaged my dual boot (7 and 8.1 Pro) using Reflect, then restored the images to my new 3.4 TB GPT array. I bought a fast 250 Gig SSD and migrated/imaged the OSes over to it. This is now my main boot drive. It is, obviously, MBR. I've retired the 3 year old original OS drive. It is labeled and safely stored as my fail safe start up OS drive. The 3.4 TB GPT array is my 'working' OS back-up. The two OSes only take up <230 Gigs, so the rest of the 3.2 TBs is data/videos. etc. Like I said the SSD is my fast boot up drive. I simply added the two back-up OSes on the GPT disk to the boot menu on the MBR SSD. When booting, I'm presented with 4 choices. Win7 SSD, Win 8.1 Pro SSD (default) and Win7 GPT array and Win 8.1 Pro GPT array. If the OSes on the SSD fail or become inoperable/corrupted (unlikely, but possible), I can boot to one of the back-up OSes on the GPT array. If the SSD fails completely (unlikely, but possible), I can use the USB stick to boot the OSes on the GPT array. What is the point of all of this you say? Despite its age, this is my working computer that I make my living on. I need it to be available, working and reliable 24/7 and it stores a ton of video and data (thus the 3.4 TB array). With this configuration, I will always be able to boot into a working reliable OS. Sometimes life is good.

PHubb · 06 Sep 2014

Further comments: This is a beautifully elegant and relatively simple solution to a problem that I imagine many people will be/are facing. Why retire perfectly good MBR BIOS hardware or suffer from the inability to boot from the new larger capacity GPT hard drives? The main advertised advantage of the UEFI BIOS is its security 'features' such as Secure Boot, Trusted Platform Module, Trusted Computing technology. It's supposed to prevent root kits from invading a relatively exposed boot process on the old MBR systems. Of course the disadvantages of all of this is potential abuse by giant corporations (MS, Intel, OEMS) in that they control the Trusted Computing technology and can force consumers onto their proprietary software/OS. This is probably not noticed by 99% of device users, but for the tiny minority of us who like to fiddle, modify, and improve systems, UEFI has presented a challenge. To boot a UEFI system, hard disks have to be formatted in the GPT partition scheme which includes a locked, hidden, FAT 32 ESP (boot) partition, a hidden, locked, 128 Mg MS Reserved Partition, and the mounted DATA partitions that OSes and files reside on. OEMs also install other hidden recovery partitions on disks, but that is not required for booting from GPT on UEFI. Unless the OEM uses a special 32 bit aware UEFI, only 64 bit OSes can be installed on UEFI. Windows 8 (and now many flavors of Linux) support Secure Boot, but not earlier MS OSes. I suppose Windows 8 with its Metro interface makes sense on small devices, but I had to do quite a bit of adjusting and fiddling to get it to function as a 'working' as opposed to a plaything OS. Windows 8 is faster than previous Windows OS and more secure. Once I got below the fluff of Metro, I discovered a pretty good OS. As has been suggested many times on the internet, MS could've done everyone a big favor by releasing a 'tweaked desktop version of 8 for those who just want a working OS. In the beginning of the roll out
of UEFI, some board manufacturers employed a type of dual BIOS that would automatically detect what you wanted to install on it. If 32 bit or on a MBR disk, you would be set for the legacy MBR setup. If on 64 bit on GPT disk, you would be setup on the new UEFI BIOS. Now that has changed. To access a legacy MBR BIOS or a CSM (Compatibility Support Module), you have to enter the BIOS setup utility (scary and not familiar to most users) and set it manually. With the locked, hidden ESP (boot) partition on UEFI/GPT systems, editing the BCD (adding an OS) has become more challenging as well. UEFI is, obviously, a workable BIOS system and is now solidly the present and future, but I admit to a pretty steep learning curve associated with it. Tasks that used to be relatively simple, now require learning and workarounds, but every once in a while we get lucky and this excellent solution for booting on MBR systems to GPT disks represents one of those times. Good Job!

milindsmart · 07 Sep 2014

Thanks @PHubb for the appreciation :) And great job elaborating too, you've expanded perfectly.

Regarding UEFI, I feel it's been more bad PR rather than actual malice... Read this mjg59 | Secure Boot and Restricted Boot. to get an idea of why Secure Boot itself is not the enemy.

About the rest of UEFI : I think you should read https://www.happyassassin.net/2014/0...lly-work-then/ .

While I'm sure you know some of this, these are interesting articles nevertheless, and can clear up some misconceptions that are widespread.

PHubb · 07 Sep 2014

Hello Milindsmart; Very interesting articles.
I wouldn't be surprised if you've seen this before, but for your viewing pleasure:
https://www.youtube.com/watch?v=V2aq5M3Q76U
-:)
PHubb

PHubb · 10 Sep 2014

@Milindsmart: I understand you and others have been working on a single GPT disk solution that involves creating a virtual
MBR disk at the beginning of the GPT disk where the MBR boot files get loaded into memory on a virtual RAM disk using a small RAM disk module by SysLinux? Has anyone had any success using this method? What are the steps? It doesn't seem that complicated from the posts by Sasha Weaver on rebootpro. Can you elaborate?

thanks
PHUbb

milindsmart · 11 Sep 2014

You're right, its not complicated at all... In fact there's another method that does away with the pre-formed image, instead it creates the necessary image on the fly and then boots, after which the image disintegrates once windows takes over.

Hack Bootmgr to boot Windows in BIOS to GPT - Page 3 - Windows 7 - reboot.pro

Use this post as a sort of index to all the landmark posts in the thread : Hack Bootmgr to boot Windows in BIOS to GPT - Page 5 - Windows 7 - reboot.pro

juched · 08 Sep 2015

So, I have been using this method of a USB key with a 512MB MBR partition to successfully boot my 3TB GPT disk to Windows 7.

However, I have noticed that my Windows 10 upgrade will not complete and I feel that the cause is the non-standard setup I am using.

Has anyone else been able to upgrade to Windows 10 with this configuration?

The setuperr.log file shows the error 0x80070003 I am getting as being related to failure to retrieve the system partition path. I know that for Windows the system disk the one with the bootloader, and the boot partition is the one with the windows files.

Also, in disk manager one of the partitions (not the C:) is marked system, even though it doesn't have a bootmgr.

Log:
2015-09-07 00:08:34, Error CONX ConX::Compatibility::CSystemAbstraction::GetSystemVolumeNtPath: Failed to retrieve system partition NT path.
2015-09-07 00:08:34, Error CONX CFreeSystemPartitionDiskSpaceChecker failed. [Failed to retrieve system volume NT path.] HRESULT = 0x80070003
2015-09-07 00:08:34, Error CONX ConX::Compatibility::CCompatibilityHost::SetScanResult: Compat scan from provider wsc:setup: failed. HRESULT = 0x80070003
2015-09-07 00:08:35, Error MOUPG CDlpActionCompat::ExecuteSysReqScan(767): Result = 0x80070003

PHubb · 13 Sep 2015

Hi; I suspect there are several issues you will have to resolve in order to successfully upgrade to Win 10 in this scenario.
1st: Win 10 upgrade will detect the GPT disk and the MBR system conflict because during the upgrade it will need to reboot the computer several times. There are several strategies you can try, but since I've not been in this situation, I don't know if any will work, but here's one possibility.
If you have an older HDD laying around, you could use this as your upgrade 'ghost' drive.
1st: Make a backup image of your Win 7 GPT partition with Macrium Reflect.
2: Restore the Win 7 image to the old 'ghost' HDD which should be an MBR disk.
3: Boot to Win 7 on the old 'ghost' HDD and upgrade it to Win 10 the normal way.
4: Once Win 10 is up and running on the 'ghost' MBR HDD, update it, run disk cleanup, etc., then make an image of it.
5: Now you have a good image of your Win 10 system ready to be restored to your original 3 TB GPT disk. At this point you have two options. Dual boot (win 7 and Win 10) by creating another partition next to your original Win 7 on the 3 TB GPT disk and restoring the Win 10 image to it or simply over writing the Win 7 partition with the Win 10 image. Macrium Reflect will allow MBR images to be restored to GPT disks and vs versa. Once you have a system partition with a full Win 10 install on it, you should be able to use the flash stick to boot to it just like with Win 7. If you're dual booting, you will have to add the Win 10 system to the BCD on the USB stick. I use a neat little program called EasyBCD to edit the BCDs on systems.