Dual Boot/ "Choice Screen"

Pez

New Member
#1
Hi all.

I was over on a different tech-support forum (http://www.tech-forums.net/pc/forum.php), and I was getting info on setting up a dual boot with Windows 7 (my primary operating system) and Windows 8 beta preview.

I have each of these operating systems installed to separate hard drives.

I tried the most recent version of EasyBCD (2.1.2), and even tried a beta version of it. Long story short: I couldn't get it to work so I could boot into Win 8; kept getting an error message along the lines of, "Windows 8 gives me the error message about possibly damaged files and wants me to put the installation disk in and also says something about not recognizing the file signature and it shows the winlogon.exe file."

So, I un-installed EasyBCD entirely, but now, when I boot up, that "choice screen" is still there, the one where you use the directional arrows of UP or DOWN to choose the OS that you want.

I was told by someone else over at that other forum I mentioned above that I have to use the Edit feature in EasyBCD to get rid of this "choice screen".

Is this true? Do I have to re-install EasyBCD and use the Edit feature?

Anyone here have any experience in doing this? Is it easy? Difficult?

I don't want to screw up my system so I can't boot at all!! :scared:

Thanks for any help or info.
Pez
 

Terry60

Knows where his towel is.
Staff member
#2
EasyBCD is not the boot manager. It's a tool for manipulating the contents of the MS bootmgr's BCD. If you uninstall EasyBCD it will not change the way the system boots any more than uninstalling Word would change the contents of any documents you'd previously created with it.
Your problem is not with EasyBCD, it's with the lack of forward compatibility of the MS bootmgr.
W7 bootmgr will not boot W8, and Vista bootmgr will not boot W7 or W8. Although all three have the same name and identical function, they have obviously progressively newer releases of the module. Each one checks the digital signature of the MS boot loader before chaining it (Winload.exe), and an older boot manager will not chain a newer boot loader.
The boot managers are backward compatible so you can boot Vista from W7 and Vista/7 from W8.
Change your BIOS to boot from the W8 HDD and you can use EasyBCD to add an entry to the W8 BCD for W7.
W8 boot is a disguised hibernation, not a real boot at all. That's how they achieve the improved "boot" time. Putting in a W7 option means that it cannot "fast" boot the older OS, so instead of chaining to W7 it will boot the system from scratch.
You might do just as well to use your BIOS boot override, and just choose to boot from one HDD or the other as required, since you have installed them independently.
The MS architecture is designed around the logic that newer systems are installed after older, and that the older system is visible at the time, so the newer system will "take over" the boot and control it, obviating any signature compatibility problems.
 

Pez

New Member
#3
Hi Terry60; thanks for the reply.

OK....some of what you said here was over my head; I didn't quite understand it.

I've familiar with "backward compatibility, but not "forward".....although I think I kind of get it.

So let me check if I think I get the gist of what you're saying:

Are you saying that I should boot from the Win 8 HDD? And then, while there, install EasyBCD on it? And add an entry for Win 7?

Will doing this help me get rid of that "choice screen" that I mentioned?

And as I mentioned in my previous post, will I end up having to use the Edit feature in EasyBCD?

I'd just like to get rid of the choice screen, and then perhaps try the BIOS override and choose which HDD I want to boot from.

Thanks for any more info.
Pez
 

Mak 2.0

Mod...WAFFLES!?!?
Staff member
#4
Terry,

Not to contradict but your information goes against what Guru has said here:

Windows 8 and EasyBCD
The New Windows 8 Bootmenu/Bootloader | The NeoSmart Files

According to him, EasyBCD is completely compatible with Windows 8 and I have personally been able to get rid of the Windows 8 graphical loader for the Win7/Vista style text based one. So I dont quite understand how you can say that the bootloader wont work forward, yet I have been able to do as such personally.

Yes if you leave the graphical loader of Win8 on there and choose another OS, the system does hard reboot itself and then boot to that selected OS and doesnt just go there, but on the same note, when I have selected Win8 from the text based selection screen I was able to easily boot Win8 with no issues. So it does seem that they are forward compatible, as the BCD hasnt changed much from the Vista days to Win7 days. Which is why the ability to add a Win7 entry if you were using Vista wasnt an issue.

Pez,

I already gave you most of the information on your topic on TF. I told you in there since you did not have EasyBCD anymore that the only way to remove the entry and get a single boot system is to either reinstall EasyBCD and modify it that way or go the Microsoft way and use the bcdedit command. I posted this almost 2 hours before you posted here asking the same thing and basically copying your post from TF to here.
 

Terry60

Knows where his towel is.
Staff member
#5
I said that Mak - viz
"Change your BIOS to boot from the W8 HDD and you can use EasyBCD to add an entry to the W8 BCD for W7"
The invalid sig is W7's problem recognizing W8.
I never said EasyBCD couldn't be used with W8.

Pez.
Yes if you don't want to see a boot menu, you'll have to go back into W7 and use EasyBCD (edit boot menu) to remove the W8 entry you put there.
Then you can use the BIOS override because each OS has its own full set of independent boot files.

(forward compatibility is a non-existent theoretical concept. Non existent because older software obviously cannot know about future changes and be expected to contain code to deal with all possible futures.)
 
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Mak 2.0

Mod...WAFFLES!?!?
Staff member
#6
Your problem is not with EasyBCD, it's with the lack of forward compatibility of the MS bootmgr.
W7 bootmgr will not boot W8, and Vista bootmgr will not boot W7 or W8.
But you state right there that you cant use the Win7 Boot Loader to load Win8, when in fact you can. Guru even says so. When you use EasyBCD and add Win8, you dont get the graphical boot loader for all your entries, you get the text based selection screen. As the graphical loader is only for Win8. So how is it that EasyBCD can be used, but at the same time cant? You have me utterly confused on this one.

The graphical loader can be disabled. Just as it can be enabled. Read the comments on the blog post, Guru posts the instructions on how to do it via the normal bcdedit commands.

So while yes, we cant program for the future, knowing that the software can still work with the future by testing it is completely valid. I have added Win8 from Win7 myself using the Beta Build. But I also dont do it via separate hard drives. My setup is via separate partitions on the same hard drive. I think his problem is more along the lines of the different drives. Since Pez just wants to get rid of the selection screen and I have no idea what he did to get the dual entries, I cant verify my suspicions. But to say that Win7 cant boot Win8, that isnt true. It is tested to work. After all it is just a selection screen. Using that method gets around the "reboot to get OS" that the UEFI Boot loader of Win8 does.
 

Terry60

Knows where his towel is.
Staff member
#7
See Guru's post 3 of the link you included Mak.
I'm talking of the generic lack of forward compatibility in a older version of bootmgr which fails to recognize the newer digital signature of a later winload as being genuine.
You presumably are talking of booting W8 from W7 after installing W8 with W7 visible in which case the W8 install will have upgraded W7's copy of bootmgr.
I am guessing that Pex installed W8 to a new HDD with W7 not visible which is why he's seeing an Inv dig sig message, in which case the answer is to boot from the W8 side if he wants to create a dual boot, or to use the BIOS override if (as it seems) he doesn't want a menu at all.
The problem only exists if W8 is installed in isolation, not if W8 could see W7 and create an auto-dual boot.
 

Mak 2.0

Mod...WAFFLES!?!?
Staff member
#8
Wouldnt using EasyBCD and having it over write the BCD do the same exact thing? Yes my installs were visable, but that shouldnt be part of it. Cause I didnt use the Win8 BOOTMGR. I never had the graphical loader.

I still dont get how installing Win8, would update my Win7 BOOTMGR if Win7 wasnt active and as stated, would recognize the file. Yeah this one has me lost cause there are things at play here that dont make complete sense.
 

mqudsi

Mostly Harmless
Staff member
#9
Alex, I think the confusion is arising from the graphical portion of the boot process. Would it make things clearer if I said graphical boot != Windows 8 bootmgr?

You need the Windows 8 BOOTMGR to boot into Windows 8, the Windows 7 one will not recognize winload.exe from Windows 8 and will give an error. Terry, contrary to what you mentioned, there actually *is* a very simple way for Microsoft to make bootmgr forward-compatible in terms of digital signature checking (that's the real issue, they don't want you loading a fake/fudged kernel, if Windows 8 used a different boot procedure to load winload.exe than Windows 7, then you're correct and there is no such thing as preemptive forward compatibility, but in fact, if they simply used asymmetric key signing (the catch: they do!), then they can actually verify that MS released that particular kernel even if it's released a hundred years in the future), however Microsoft has for reasons known only to them, chosen not to do it this way.

Perhaps my blog post was unclear, for that I apologize: Windows 8's BOOTMGR *facilitates* but does not necessarily enable the graphical boot loading. i.e. you need Windows 8's BOOTMGR for the new boot environment, but using Windows 8's BOOTMGR does not guarantee the presence of the new boot environment.

BOOTMGR, combined with the BCD file, winload.exe, and a host of other entry-related things determine whether the new boot environment is used or not. EasyBCD configures the BCD file in a way that is compliant with Windows 7, not Windows 8. This means that Windows 8's boot functionality is reduced to the "common denominator" experience: the simple boot, but that's on top of Windows 8's BOOTMGR, not instead of.

If you install Windows 8 normally, regardless of whether Windows 7 was on a different or same drive, the BOOTMGR file will (or should) be upgraded from the Windows 7 BOOTMGR to the Windows 8 BOOTMGR. There are exceptions: if you manually change the boot device in the BIOS, Windows 8 setup will not detect the Windows 8 BOOTMGR as being on a bootable partition, and as such, will think it is of no moment and ignore it entirely from the upgrade procedure. This is the cause of the invalid signature error 99% of the time. The other 1% is a bug in Windows setup where BOOTMGR is not correctly upgraded, we see this sometimes in Service Pack updates.

To answer the OP's question: the error regarding digital signatures is from Microsoft, and nothing to do with EasyBCD. The screen itself is also from Microsoft, however whether you see the second entry for Windows 8 on there can be either you or Windows 8 setup to blame, depending on who added that second entry. If you change boot devices from the BIOS, odds are, you're the one that added that from EasyBCD. In either case, you can get rid of the "choice screen" as you call it by reinstalling EasyBCD, deleting the entry, and then uninstalling EasyBCD once more if you so choose. I hope this clears up all the confusion regarding the Windows 8 bootloader.
 

Terry60

Knows where his towel is.
Staff member
#10
My parenthesized footnote to post #5 is of course a generality about the concept of forward compatibility in response to the query in post #3.
EasyBCD for historical example could not have known of the W8 changes in advance of the DP (despite the irate users who complained bitterly on day one "why don't you state explicitly that it won't work with the GUI")
You're right of course that the Inv Dig Sig problem is an unnecessary "own goal" on MS's part (or maybe deliberate design - they do seem determined to enforce a sea change on the entire PC community with W8) when Vista/7/8 are basically just successive builds of the same product, but as with the XP - Vista change, there does come a point where even the same development team can't predict what their own software will have to cope with at some point in the future. Moore's Law more or less guarantees that future software will have to work quite differently than it does today. The developers of W95 would have boggled at the thought of 32Gb RAM and 3Tb HDDs and who knows what W10 will look like?
 

mqudsi

Mostly Harmless
Staff member
#11
Completely agreed, Terry. Just interesting that MS chooses to not exercise the option of forward compatibility even when it's possible.
 

Mak 2.0

Mod...WAFFLES!?!?
Staff member
#12
Thanks Guru. That makes much more sense now.