How can I make a bootable DVD?

SIW2 said:

bootsect writes the partition boot code , it can be nt52 or nt60 code.

Step 6 not needed if you formatted the partition from diskpart.

Using Dispart
Clean writes the boot code

I actually once "on a rainy day" went through all the steps I mentioned earlier observing with Hex editor.
I think Bootsect is a tool from a bygone era. Of course you can use old tools if you want.

Hmm...
I thought Bootrec replaced Bootsect for post XP NT but if it is alive and well in Windows 8 then I retract my "by gone error statement". Then again given W8 is a little regressive I'm not sure. I certainly didn't think Bootsect was new.
It certainly isn't needed to create a bootable USB from the BIOS perspective as the OP was suggesting. I suspect it simply was doing no harm but no good. Maybe some of the "Bootsect" functionality is embedded in diskpart functions and bootrec which can only be accessed from the system repair disc's boot.wim file??? ie. it can rebuild the MBR boot code but so either "clean" from diskpart or bootrac /fixmbr. To confuse the discussion further bootrec is only accesible
A nice little read
Difference between bootrec and bootsect - Neowin Forums

Conclusion:
Bootsect is not needed for a bootable usb under Windows 7. Of course for a W7 environment you need to add the bootmgr and Boot folder containing the BCD plus a source folder to actually do anything.

mjf said:

I always thought Bootsect was related to NTLDR (NT Loader) and required for XP.
Here is my understanding for W7

Clean ------Inserts bootcode in the MBR
Create partition primary------sets adds partition entries in the MBR
active--------sets the active 08 flag in the MBR
format------ sets the format code in the MBR (eg 07 for fs=ntfs) and adds the file system
assign------ allows a non specific letter to be added when the USB is plugged in

That makes the USB bootable from the BIOS's point of view

After that you need something to boot into which you get by copying the system repair DVD contents.
(Works for me)

You would need ntldr if multbooting a drive to include XP.

Maybe other members would care to comment.

Another text I found in my folders:

For Windows 7 Ultimate X86 SP1 IE9 Net4.5 Sep 2012:
(- this one says clean only removes partitions, I take it it does both?d
update: i.e. this does seem to support that it does MORE then just wipe the partition info.)

Quotation marks denote the command to type, do not type the actual "quotation marks"

Launch the DiskPart utility by typing "diskpart" at the Start Menu.
"list disk" //command to find the drive with appropriate size.
"select disk 1" //where the "1" is actually the corresponding number of your USB drive.
"clean" // removes all partitions
"create partition primary" //bootable partition
"active"

"format fs=fat32 quick" //yep fat32 boots fine with no boot sector using this method (???
update: - it looks like the author is underestimating the "clean" function here)

"assign" // command gives the USB drive a drive letter, making it easy to access from Windows Explorer
"exit" //Yer done with command prompt

Then you can copy everything from the Windows 7 installation DVD onto the USB key (a simple drag and drop will do).


added: bootsect in Win7 64bit folder is 112,640 bytes and in x86 folder is 97,280 bytes and not sure what it is for XP because it got "bak'ed" on a BCD install...

SIW2 said:

If you use diskpart to initialise/format it is done automatically.

Bootsect is there for working on/repairing/changing the code on drives that have already been initialised, and partitions that are already formatted......

I have never used bootrec for anything.

In describing the the USB preparation steps I described above I started with a fully zeroed (inc MBR) USB - ie Raw. The clean function will insert MBR boot code but this is only part of an MBR. The other steps address the other MBR partition table parameters. In addition to creating a file system the format command sets the format type identifier byte in the MBR.
I will experiment and see if "format" would also generate the MBR boot code.

I never use Bootsect but often use Bootrec - each to their own.