Understanding Windows Boot Manager

iclick · 12 Jan 2013

I have about 30 years of experience building and maintaining computers, but I'm working with Windows 7 x64 for the first time in a new build that's only a month old. So far I'm impressed with Win7 with modern hardware compared to XP x86 using 2009-vintage hardware, an OS I became very familiar with over a 10-year period. There are a few things that I'm unclear about, and one involves the BIOS and the boot order. First, some pertinent hardware info:

Motherboard: Gigabyte GA-Z77X-D3H (Z77 chipset, LGA 1155)
CPU: Intel 3770K
RAM: 2 x 8gb Kingston HyperX Black (1600)
BIOS: f16

From the BIOS splash screen I have some options, one of which is F12 which launches the "Boot Menu." That reveals a list of eight items:

1. Windows Boot Manager
2. Windows Boot Manager
3. P5: (DVD drive)
4. Lexar SD (Dual-slot USB card reader)
5. Lexar CF (Dual-slot USB card reader)
6. Crucial M4 (SSD that contains the OS)
7. WD RE4 2TB SATA (storage only)
8. WD Green 2TB SATA (storage only)

Another option in the BIOS splash screen is the standard DEL for Setup, which looks more familiar. What I see here under BIOS Features > Boot Option Priorities are a list of five items:

1. Windows Boot Manager
2. Windows Boot Manager
3. P0: Crucial M4 (SSD)
4. Disabled
5. Disabled

Despite quite a bit of searching I'm still baffled about the "Windows Boot Manager" and why it shows up twice in the boot order. Further, when I select the SSD as the first item in the boot order the computer will not boot. Let's keep in mind that everything seems to be working fine, but I am not content being ignorant of what's going on in the boot process.

I suspect that two iterations of "Windows Boot Manager" may be present because about three weeks ago I accidentally allowed the system to boot with both the SSD and a cloned drive running. I had just cloned the SDD to a SATA HDD for backup purposes with Acronis True Image and it rebooted with both drives active, which is something I know better than to do and did so quite by accident. Nonetheless, when this happened in the old XP machine there was never a problem. In this case when it booted it apparently had done so from the cloned drive, not the SDD, and when I powered down the hot-swappable SATA HDD everything went black on the screen. I rebooted with the clone out of the system and all was well.

What I would like to know is:

1. Exactly what is the Windows Boot Manager as it relates to the boot order in the BIOS?

2. Can I disable the second instance of Windows Boot Manager?

3. Can I manually establish only the SSD and DVD burner in the boot order, as these are the only two drives from which I would routinely boot. If so, what would be my boot order considering the SSD appears to be unable to boot on its own? BTW, the Lexar card reader and two 2TB HDD's will never be boot devices, so I would like to eliminate these from the list, and I can't imagine ever booting from anything else, unless the SSD becomes inoperable and I must use a cloned HDD.

4. Why won't the system boot when the SSD is selected as the first boot option?

5. In the BIOS under CSM Support the default setting is "Always." There are options under CSM and I'd like to know more about them (option and current setting):

a. Boot Mode: UEFI and Legacy
b. PXE Boot Option Control: Disabled
c. Storage Boot Option Control: Legacy only
d. Display Boot Option Control: Legacy only
e. Other PCI Device ROM Priority: UEFI OpROM

I know this is long, but I hope enough of you Win7 gurus read it and respond so that I can understand this better. Thanks in advance.

AddRAM · 12 Jan 2013

Post a shot of disk management so we can see your layout.

Screenshots and Files - Upload and Post in Seven Forums

iclick · 12 Jan 2013

AddRAM said:

Post a shot of disk management so we can see your layout.

Thanks for the quick reply. The requested screen shot is attached. Notes:

F: = Lexar USB card reader (CF slot)
S: = Lexar USB card reader (SD slot)

You'll also note that I have the page file split between C: (1gb) and D: (16gb). The rest should be self-explanatory.

AddRAM · 12 Jan 2013

Is this brand new and that`s the way it came ? Drive C and B should be switched and you should change that drive letter from B to E.

You want your boot disc parttition C to be disk 0.

Change your DVD drives to the last letters of the alphabet first. Then you can rename B to E

iclick · 13 Jan 2013

AddRAM said:

Is this brand new and that`s the way it came ? Drive C and B should be switched and you should change that drive letter from B to E.

Whenever I install an OS I always start with a bare system--i.e., nothing else except those hardware items the system needs to function--which would necessarily be two drives (the SSD that is now C: and the DVD that is E:). After that I installed B: and D:, but I don't recall if C: ever was Drive 0 except when the OS was originally installed.

You want your boot disc parttition C to be disk 0.

Why?

Change your DVD drives to the last letters of the alphabet first. Then you can rename B to E

I've always had E: as the DVD drive, so what's the harm of leaving the drive letters as they are? I'll admit I do normally see the boot disk as Drive 0, but how does this affect anything related to the original problem? I'm not arguing, just trying to clarify.

gregrocker · 14 Jan 2013

What I notice is that you have a second page file on Disk1. I would turn it off using Change Virtual Memory Paging File.

The concern on OS HD not being in Disk0 is on an MBR disk where repairs can derail the System boot files to the first partition on first HD in some cases. I don't believe it applies with EFI installs.

Due to legacy lettering of floppy drive as A and B, Win7 indexing does not index the files on either of those drive letters so its best practice not to use them. And it is best to have your data drives indexed so that you can find anything quickly by typing into the Start Search box a key word:
Index Locations - Add or Remove
Index - Rebuild - Windows 7 Forums

iclick · 15 Jan 2013

gregrocker said:

What I notice is that you have a second page file on Disk1. I would turn it off using Change Virtual Memory Paging File.

Win7 wanted a 16gb page file on the C: drive, which was taking up a big chunk of real estate there where it is not plentiful, so I decided to put 1gb there (it insisted on at least 800mb) and 16gb on D: where I have much more space. I decided that with 16gb of RAM the page file probably wouldn't be much of a player and having it on my slowest drive wouldn't impose a hit on performance. I wouldn't mind putting it back on C: if there is a good reason for it.

The concern on OS HD not being in Disk0 is on an MBR disk where repairs can derail the System boot files to the first partition on first HD in some cases. I don't believe it applies with EFI installs.

I guess it is happy there, as everything works fine. I'm just not used to seeing C: anywhere except as Drive 0.

Due to legacy lettering of floppy drive as A and B, Win7 indexing does not index the files on either of those drive letters so its best practice not to use them. And it is best to have your data drives indexed so that you can find anything quickly by typing into the Start Search box a key word:
Index Locations - Add or Remove
Index - Rebuild - Windows 7 Forums

The search list (Control Panel > Index Options) shows B: and it is enabled, but when I search for something over there it doesn't find it. It isn't a big deal, as all I have over there are videos and I use a separate database app to catalog and find things over there anyway.

At this point I'm okay with Windows Boot Manager and EFI taking control of the boot process, as it apparently speeds things up over the legacy method, and I don't have much choice anyway. It appears that to change it to the legacy method would involve reinstalling Win7 again, which just ain't gonna happen. I'd still like to know why I have WBM as the first and second items in the Boot Menu (Gigabyte AMI EFI), and either one launches Win7 normally. There doesn't seem to be a way to change this by deleting one.

gregrocker · 15 Jan 2013

I would query your mobo maker as every EFI mobo is different. You can email, chat or use their Forums. If it's within a year of purchase you have phone tech support to rely on.