Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.


Windows 7: can someone explain to me how a mbr , vbr & ntloader works..

22 Jun 2010   #1
firesh

window 7
 
 
can someone explain to me how a mbr , vbr & ntloader works..

hi ,

No its not the wrong thread or so i know whr i am writting.. please forgive me for the title.

i am writting this is becoz i actually would like to know the difference between all this 3 things and what are they in lay mans term n whr there are located whether it is all combined into a thing called MBR (master boot record) or they are individual entity or how is it like ?.. please explain someone.. badly need to know..

i tried understanding myself alot by reading sooooooo soooo many websites everyone seem to say the same which makes sense but i am jus confused on how this works.. a hint or a person explaining it to me would be better as i am new in venturing to this field learning up and picking up my skills.

the reason why i actually wanna learn up this is becoz i have a system setup that looks somewhat like this :


--> Part 1 : SWAP
--> Part 2 : STATE (you can ignore jus a empty space)
--> Part 3 : Changeable Partition (Where the OS will reside)
--> Part 4 : a linux os (jus for some usage)


so, what i wanna do here is i would like install my Win 7 on the fly by unzipping the dump file (gotten from linux dump command) into Part 3 (ntfs of course), and then boot up win 7 on the nx boot (by me change the active partition to 3)..

the problem here is i dun really understand how MBR / VBR / NTLOADER works and whether this possible to do for win 7 !!... WinXP with FAT32 was easy..

can someone feed me with some knowledge .. please

is MBR contain VBR and NTLOADER all in or they are seprate hex that loads one after another or how the heck this thing works.. yea i know they are assembly which i hv no knowledge on .. but i am pretty sure there is some easy way out whr i can jus extract that hex codes to directly to be flushed in my HDD and works as long as the partition table maintains ...

can someone point me some clues here....


My System SpecsSystem Spec
.
22 Jun 2010   #2
Adrian

 
Follow this link

Quote   Quote: Originally Posted by firesh View Post
hi ,

No its not the wrong thread or so i know whr i am writting.. please forgive me for the title.

i am writting this is becoz i actually would like to know the difference between all this 3 things and what are they in lay mans term n whr there are located whether it is all combined into a thing called MBR (master boot record) or they are individual entity or how is it like ?.. please explain someone.. badly need to know..

i tried understanding myself alot by reading sooooooo soooo many websites everyone seem to say the same which makes sense but i am jus confused on how this works.. a hint or a person explaining it to me would be better as i am new in venturing to this field learning up and picking up my skills.

the reason why i actually wanna learn up this is becoz i have a system setup that looks somewhat like this :


--> Part 1 : SWAP
--> Part 2 : STATE (you can ignore jus a empty space)
--> Part 3 : Changeable Partition (Where the OS will reside)
--> Part 4 : a linux os (jus for some usage)


so, what i wanna do here is i would like install my Win 7 on the fly by unzipping the dump file (gotten from linux dump command) into Part 3 (ntfs of course), and then boot up win 7 on the nx boot (by me change the active partition to 3)..

the problem here is i dun really understand how MBR / VBR / NTLOADER works and whether this possible to do for win 7 !!... WinXP with FAT32 was easy..

can someone feed me with some knowledge .. please

is MBR contain VBR and NTLOADER all in or they are seprate hex that loads one after another or how the heck this thing works.. yea i know they are assembly which i hv no knowledge on .. but i am pretty sure there is some easy way out whr i can jus extract that hex codes to directly to be flushed in my HDD and works as long as the partition table maintains ...

can someone point me some clues here....
MBR refers to a Master Boot Record.
Follow this link for further information to help you discover the answers you seek.
Master boot record - Wikipedia, the free encyclopedia

Regards,
Adrian
My System SpecsSystem Spec
22 Jun 2010   #3
firesh

window 7
 
 

Thats the first url i wen n look for ... but the problem is i dun really understand. mayb some expert human explanation with simple words or so would be more meaningful.. anyhow i will try looking again if anything strikes me ..
My System SpecsSystem Spec
.

22 Jun 2010   #4
Fumz

7 Ultimate x64
 
 

The master boot record is the very first sector on a hard drive. It contains the partition table (which tells where and what's on each partition) and the startup bios. The startup bios asks CMOS what is the first boot device? It finds out which device is to boot first, then finds out where that device is on the partition table, then it goes to that partition and loads the OS.
My System SpecsSystem Spec
22 Jun 2010   #5
Bill2

Windows 7 x64 pro/ Windows 7 x86 Pro/ XP SP3 x86
 
 

1) What exactly do you want to do?

2) Let me try narrating the theory a bit, to the extent I understand. The win7 boot process is a series of small programs running one after another. The first of course is the bios. The bios is pretty good at locating the next program (whether on hdd, dvd, usb etc.) but if the OS is situated on the hdd, then the bios will look in only one particular place on the hdd. This is the MBR located on the first 512 bytes of the disk.

Now, the MBR is made of 2 parts- the boot program and the partition table. The partition table tells you which partition is ACTIVE. The bootprogram reads that, goes to the beginning of that partition and runs the program located there- the VBR. The VBR, unlike the programs before it is OS specific.

The next step is to actually start windows- this consists of 2 steps-selecting the OS and loading the OS. Selection is done by the bootmgr, which is located in the root of the concerned partition. Loading is done by the file called winload.exe which is located in the System32 folder. So, note that NTLDR no longer operates, its functions are performed by bootmgr and winload.exe.

3) Physically, the MBR is right at the beginning of the drive and it is separate from the partitions located after it. The VBR is a part of the partition and is located at the beginning of the partition.
My System SpecsSystem Spec
22 Jun 2010   #6
firesh

window 7
 
 

ok cool.. thats better but .. ok looking at the website given by "Adrian" i got something on my head finally ...

was reading it and from my knowledge as far as the read goes ... MBR and VBR are 2 different thing ... MBR is the first in ur HDD n VBR is first on the partition that you are booting up .. am i right ?..

if yes.. then lets proceed, meaning to say without me touching my MBR .. and selecting partition 3 as active which eventually triggers the MBR to change the active partition hex to partition 3 in the partition layout ... it will boot up partition 3.. and if i can find the first CHS(Cylinder, Head, Sector) of my partition 3 and me dumping (writting ) VBR of windows 7 there.. then it would actually boot my Windows 7 ?????

is this correct .. can i know whether is is correct.. jus very much enthusiast about knowing it...
My System SpecsSystem Spec
22 Jun 2010   #7
Bill2

Windows 7 x64 pro/ Windows 7 x86 Pro/ XP SP3 x86
 
 

You seem overly concerned about the physical layout of things. You want to install win7 and boot from it? Mark the win7 partition active in Disk Management/ through Diskpart/ through 3rd party utility, then reboot from the Win7 install dvd. Run Startup repair 3-4 times, then you should be able to boot normally from the OS.
My System SpecsSystem Spec
22 Jun 2010   #8
firesh

window 7
 
 

Bill2 ... i love u ... hahaha.. now that kinda explanation that i was looking for .. fuh ! that explain to me lotssss...

so in this case of mine .. if i manage to find the VBR of window 7 and place it at my partition 3 .. it would load my windows 7 ??..

or does it goes after this... thank you all for making me understand on this portion of the software world ..

once i get to know on all this details .. then i can try figuring out tools that will allow me to customize this and therefore allow me to understand more deeper into this..

coz my main aim right now is to boot windows 7 but re-placing back the VBR -> bootmgr -> winload.exe into the correct positions to allow a windows 7 boot up as thou nthing was modified .. in this case i can actually zip the OS n keep and it i can restore it into my third partition anytime i wan jus like a pendrive plug n play OS... (sounds dumb yea but its jus something i am working on (my own interest) which is kinda interesting on knowing the flow of all this details)

i dun wanna use and third party tools... coz i am looking into a horizon of linux repairing VBR (or wat so ever the process of windows boot up is) ... i would love to hv linux repairing windows .. that would be super cool.. of course u will tell me use fdisk (i dunno this can be used or not .. but in terms of windows 7 installed in a non-first-partition, not sure if fdisk can repair it, not even sure if fdisk can actually do anything for it first of all)


***VBR stands for Volume Boot Record NOT Variable Bit Rate!!
My System SpecsSystem Spec
22 Jun 2010   #9
theog

Microsoft Community Contributor Award Recipient

ME/XP/Vista/Win7
 
 

Are you trying to do a Win7 boot repair if yes,Try this:


Startup Repair
Note: You may need to do startup repair 3 to 4 times.

System Repair Disc - Create
System Recovery Options
Repair Install
My System SpecsSystem Spec
23 Jun 2010   #10
firesh

window 7
 
 

Nope... i am not trying to repair but i am actually trying to tear all pieces apart and then join them back just for me to understand the flow of how things are working behind physically..


what i am tearing here is .. i have my own custom MBR which has options such like

F1 - partition 1
F2 - partition 2
F3 - partition 3
F4 - partition 4

so my partition 4 has a "dump" copy of the windows 7 in ".tgz" format

so what i am trying to do here is , in my partition 4 , mount to partition 3 , untar the ".tgz" file into partition 3 (which actually is the windows 7 files , but becoz u do a dump so ur windows 7 mbr / vbr (am confused here).. is gone coz my partition 3 is always changing formats !...) ..moving forward .. then once the untar is done.. i set the partition 3 to active on the nx boot it should boot to windows 7 with partition 3 being active .. but i know now u guys will say it wont work coz it doesnt hv the (windows 7 VBR (os specific vbr -8192kb) but infact i kinda hv the vbr 8192kb which i extract earlier wen i installed windows 7 manually on partition 3) .. taking that binary file.. i actually do a dd

dd if=/bootsect.bak of=/dev/sda3 bs=8192 count=1

and set my partition 3 active

so nx boot it goes to partition 3 .. but the problem now is it doesnt boot up my windows 7 .. i am figuring out wat is the problem here...


if u follow the MBR Partition Scheme it says something like

MBR -> VBR of a specific partition -> loads the OS

but in my case my MBR is custom that point to the partition .. once its in the partition the VBr takes over .. then os loading should start (in my case it doesnt but instead i jus get a blinking " _ " or " A disk read error occurred. Press Alt+Ctrl+Del to reboot" - which the error resides in windows 7 VBR !)


****VBR here stands Volume Boot Record NOT Variable Bit Rate !!!
My System SpecsSystem Spec
Reply

 can someone explain to me how a mbr , vbr & ntloader works..




Thread Tools




Similar help and support threads
Thread Forum
Could someone explain this
I was on a web site that I needed to press print screen and a small snuppet appeared and disappeared so quickly to the right of the screen i had no chance to react, except i did catch some words to the effect " if you want to see ...." Now does anyone know where that 'screen' went to read it? I...
General Discussion
Can someone explain this to me please
This is the security log from my router. Do I have a virus or malware problem ? 192.168.2.4 is my laptop wireless connection. Your advice appreciated.
System Security
Please to explain.
Please to explain wht this error is. Its the only error in my event veiwer. ty
BSOD Help and Support
Could Someone Explain
I would appreciate it if someone could please explain the difference between a disc image and cloning a HDD in simple speak as I can't wrap my non tech brain around it
Chillout Room
Please, explain this.
when i was starting up my laptop i got this message.... " Error occured: Canot registry tray icon. Error:1008 (An attempt was made to reference a token that does not exist.) " could anyone explain this?
General Discussion


Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 19:19.
Twitter Facebook Google+ Seven Forums iOS App Seven Forums Android App