A few questions about EasyBCD's bootloader options, and Startup Repair

#1
Ok, I would like to know what all the options in the "Manage Bootloader" section of EasyBCD do, as well as Startup Repair on the Vista DVD, so when we help users on the forums, I'll be more qualified to help with booting problems.
For instance, in another thread CG mentioned that the "Uninstall the Vista bootloader" feature includes the bootsect command to put the bootsector that's compatible with "ntldr" on whatever partition is "active". Ok, but can it also recreate the XP boot files (boot.ini, ntldr, and ntdetect.com)? The same question goes for the "Reinstall the Vista bootloader" feature: Does it recreate the Vista boot files (BCD, bootmgr, and winload.exe), and does it also include the bootsect command to put Vista's bootsector on the "active" partition? And what about the boot code in the MBR? Will it put either code that is compatible with Vista, or code that is compatible with XP, in the MBR, depending on which option you select?

I'm also wondering what all Startup Repair on the Vista DVD can do. For instance, I know for sure it can replace XP's bootloader in the MBR with Vista's, since I have experienced it first hand while working out my own triboot. I'm also pretty sure it can put the bootsector that is compatible with "bootmgr" on the "active" partition, if it turns out XP's bootsector is there instead. But can it recreate the Vista boot files? Or does it just *fix* existing ones?

Thanks in advance.

Jake
 
#3
Really? That's all? And I assume you mean both Startup Repair and the EasyBCD features?
 

JustinW

Super Moderator
Staff member
#4
Startup repair might replace the files, but thats MSes own program and the files are included on the disc.
 

Terry60

Knows where his towel is.
Staff member
#5
Startup repair certainly replaces bootmgr, recreates the BCD and writes the Vista PBR into the boot sector, if necessary.
It only seems to do one of them per pass though, if more than one is needed, hence the "repeat 2 or 3 times"
 
#6
Startup repair certainly replaces bootmgr, recreates the BCD and writes the Vista PBR into the boot sector, if necessary.
It only seems to do one of them per pass though, if more than one is needed, hence the "repeat 2 or 3 times"
Alright. Thanks Terry and Justin. That is what I needed to know. :smile:
I guessed as much with Startup Repair since the advice for users to run Startup Repair 2-3 times when there's a problem with the BCD or bootmgr, etc., always seemed to work. I also remember it recreating the BCD for me, once before in the past. Do you know though if Startup Repair can recreate the winload.exe file? That is really what I meant to ask. :wink:
But I must admit I was not sure whether or not EasyBCD recreates the boot files or not, when you tell it to either "Reinstall the Vista bootloader" or "Uninstall the Vista bootloader". I have never actually tried them myself, since I have never had a need to, but I certainly would have expected EasyBCD to recreate the boot files. But I guess the reason why it doesn't have that feature is probably due to legal issues with MS's copyright protection?

Jake
 

Terry60

Knows where his towel is.
Staff member
#7
Easy can reset the PBR to either Vista or XP version, and it can recreate the BCD, but they're separate commands on different pages.
 
#8
Alright. What about the MBR? I'm assuming since the button in the "Manage Bootloader" says "Write MBR", that it can write Vista's boot code to the MBR?
 

Terry60

Knows where his towel is.
Staff member
#9
Yes it says MBR, but I'm sure its actually the PBR that gets rewritten in the boot sector. Guru will correct me if I'm wrong no doubt.
I think it's one of those cases where the MBR, IPL and PBR get lumped together under the umbrella title of MBR, since more people understand that there is an "MBR" that initiates the boot sequence, than would understand the actual chain before the boot manager gets fired up.
 
Last edited:
#10
Yes it says MBR, but I'm sure its actually the PBR that gets rewritten in the boot sector. Guru will correct me if I'm wrong no doubt.
I think it's one of those cases where the MBR, IPL and PBR get lumped together under the umbrella title of MBR, since more people understand that there is an "MBR" that initiates the boot sequence, than would understand the actual chain before the boot manager gets fired up.
BIOS>IPL>PBR>bootmgr>BCD>winload.exe is the booting chain for Vista.
BIOS>IPL>PBR>bootmgr>BCD>ntldr (with the help of boot.ini and ntdetect.com of course) is the booting chain for XP (when dual-booting the two).

Also, from what I understand about the Microsoft IPL (after reading the multibooters site again) is it is the same for both XP and Vista, but what changes if you install Vista after XP is the XP PBR (which looks for the ntldr) gets overwritten with a Vista one (which looks for the bootmgr file that Vista uses). Now, one thing I not quite sure about though is if there is a specific IPL for Windows, and a specific one for Linux...? Obviously, it seems that there is since you can install Grub to either the partition's bootsector, or to the "MBR"...but I am wondering on second thought if that's an example where the terms "MBR" and "PBR" are mixed up?
I'm assuming the process to boot Linux on a Linux-only computer would be essentially the same as a Windows computer with a single OS:

BIOS>IPL>PBR(most likely one that looks for whatever file it is that is Linux's boot manager)>boot manager (which reads from the menu.lst to figure out where the OS files are, so it can load them)

Though I'm a little unsure on whether Linux has a separate boot manager and a separate bootloader, like Vista has for instance, or if it has a single boot file that functions as both (like XP)...?

Jake
 
Last edited:
#12
Ok...I found the answer to my Grub question.
There is indeed an IPL that is specific for Grub, and I believe it is the "stage1" image file which ends up getting installed to the partition instead if you chose to Grub there instead of the MBR (though maybe it actually installs "stage1" to both, even if telling the installation setup to install Grub to the MBR). The "stage2" file is the Grub boot manager/bootloader (yes, apparently its both...), which handles the menu.lst entries, and is what actually starts up the OS kernel. There is also a "stage1.5" file that starts the "stage2" since it can't start by itself.
Additionally, it seems I was right about the IPL (itself) being the same for both XP and Vista, though from what it sounds like, there is some kind of "disk identifier" in the MBR that Vista (as well as Win 7) depends on, and which will get screwed up if you use fdisk /mbr on it. :wink: Maybe that's why in my case I had to run Startup Repair on my computer, after installing XP (along with its boot files) to its own separate partition, and then changing the "active" partition back to Vista's so I could boot Vista again, though the PBR was fine. Maybe the XP setup screwed around with the disk identifier.

Jake
 
Last edited:

mqudsi

Mostly Harmless
Staff member
#13
Yes, Terry is right. When you opt to fix the MBR in EasyBCD, it actually fixes both the MBR and the Bootsector.

Addendum:

Jake, read the Wiki. It's a bit out of date, but it has a lot of info.
 
Last edited:
#14
Yes, Terry is right. When you opt to fix the MBR in EasyBCD, it actually fixes both the MBR and the Bootsector.
Ahh...so it does perform actions on the MBR as well, then? I'm assuming you mean it rewrites the IPL? Which brings me back to the former question I had in mind...is the IPL the same for both XP and Vista, or are there differences, and the XP one has to be replaced with the Vista one in order to chain to the Vista PBR? I'm still unsure about that, since some things that I read seem to suggest that they are the same (such as the multibooters site), and other things almost (but not quite...) make it sound like they are different.
Addendum:

Jake, read the Wiki. It's a bit out of date, but it has a lot of info.
Well, I'll admit I haven't read all of it as yet, but I *have* read a lot if though already. :wink: For instance, I have read the sections about recovering the Vista bootloader with the DVD, and with EasyBCD. I have read the sections on NeoGrub, as well as what little info I could find there on Linux, and I have read other sections as well...
I would have certainly never even started this thread if the wiki had answered all of my questions and clarified the things I mentioned here. :smile:

Jake
 
Last edited: