3 replies to this topic

[pajenn]

I've used bootsect.exe to install nt52 and nt60 boot codes to USB flash drives and virtual hard disks, but I wonder if there's a way to check what boot code is currently installed or whether a system's MBR is nt52 or nt60 compatible? (The main system I use is Windows XP, but I have it set to multiboot so that I can load various grub4dos, vboot and win7 VHD options as well...)

Is the boot code (nt52 or nt60) the same as the MBR? (I've seen them used interchangeably at times, but haven't found a clear definition.)

Edited by pajenn, 08 April 2011 - 11:57 PM.

[doublesvsoop]

Try using BootICE to get info about your mbr.

[steve6375]

The MBR (Master Partition Record) contains code which finds out which partition in the partition table contained within the MBR sector is the active partition (marked as active in the table entry), and then loads the first sector of that active partition into memory. The first sector of a partition is the first sector of the PBR (Partition Boot Record, sometimes also called VBR Volume Boot Record). The code in the PBR is responsible for loading the boot file (NTLDR, IO.SYS, KERNEL.SYS, BOOTMGR, etc.) - so it is this PBR sector you need to look at.

If you are using RMPrepUSB, you can use the USB Info button to look at the MBR (LBA 0 - Logical Block Address 0 which is always the first sector on a disk) and see which is the active partition and what sector it starts at (usually either 32 or 63). Then hit the USB Info button again but this time ask for the PBR sector (e.g. 32 or 63). You should then see some text in the PBR boot code (near the end usually) which has the name of the file it is looking for (e.g. BOOTMGR if Vista/Win7/WinPE v2/v3).

HTH

[pajenn]

Try using BootICE to get info about your mbr.

Thanks. Bootice says: "Current MBR Type: Windows NT 6.x default MBR" - I must have 'updated' it by accident when installing Windows 7 into USB flash disks and virtual hard drives... but it's better anyway.
And Bootice looks like a great tool.