boot sector contains drive geometry info?

#1
Hi there troopers.

I once had a dual boot system (Vista & XP) which I set up with EasyBCD.

This was great, but I wanted to reinstall my OS' and I now had 2 hard drives and wanted to put one on each, independent of the other and choose which to boot just using the BIOS menu.

To cut a long story short I didn't realise that I should have hidden the partition with XP on it when I later installed Vista to the second hard drive. Vista's set up program therefore did the usual thing and took over, plonking its boots, boot folders, bootmgr, mbr's all over my XP partition.

To cut a still longish story short by some half again--I fixed up Vista, its mbr and bootsector so that it would boot all fine and dandy and enthusiastically. That's not my problem. My problem is that the MBR and bootsector on my XP drive/partition (same thing cause I have 1 partition per hard drive) were overwritten with Vista ones.

Fine, I thought, I will just boot into Vista RE using my install disk, and then issue the
x:\boot\bootsect.exe /nt52 d:
(Where d: is the drive letter of my XP partition/drive)
... thus rewriting a boot sector "compatible with NTLDR"
Wrong! XP now BSOD's instead of booting. Sometimes it goes into CHKDSK, finds a few errors in the partition table, then it reboots, then it BSOD's again...

OK, so I thought, I'll go into XP's recovery console (using my XP install disk) and issue the:
'fixmbr /device/harddisk1/partition1' command.
I did this.
It warned me not to do this.
I did it anyway. I restarted the computer.
My XP partition had now become totally unreadable, I now got 'Invalid system disk' when attempting to boot XP.
But a funny thing happens. One of the programs I have got can read the XP drive, and I can see my folders on it. And this program gives the option to get the information from the MFT or the boot sector. (I do not pretend to understand what that means.) But when I choose 'MFT' I can see my files. When I choose 'boot sector' I can see nothing, a blank screen.

OK, so I thought, I'll go into XP's recovery console and issue the fixboot command.
I do this.
fixboot c: (where, trust me, c: is now the XP drive)
My XP drive instantly becomes readable. Some damage is done to the file system but I can recover my data and reinstall XP, this time doing it all properly. All is well.

But what gives? Can anyone shed light on why Vista's recovery tool, specifically the bootsect.exe command, which is supposed to restore the XP boot sector to an NTLDR compatible one, actually seemed to encourage damage to the file system on my drive?

All is well now, so don't knock yourself out, but I can't understand what the purpose of the /nt52 switch in the bootsect.exe command is for. I found the article around here which warns that bootsect.exe cannot restore the XP mbr. I understand that, bootsect.exe only works on boot sectors. But if the bootsect.exe command cannot restore the XP mbr and can only restore the XP boot sector, which is then risky to use because it has to be matched by an XP mbr then what is the point of it? Or more specifically, its /nt52 switch?

I apologise for the inconvenience of the length of this post.
 

JustinW

Super Moderator
Staff member
#2
Isn't /nt52 supposed to be /nt50? And bootsect is mainly for working with XP so it couldn't be called one of Vista's tools. Just stick to disconnecting or disabling in the BIOS during installs to ensure the full OS and its boot files get placed where you want them.
 
#3
XP can easily see a repair install in order to see that version running again. http://www.michaelstevenstech.com/XPrepairinstall.htm

Once XP is up and running again you can correct the Vista problem by shutting down, unplugging the XP boot drive, and installing a fresh copy of Vista on the second drive again seeing all boot files and mbr entries placed there. Following that and replugging the XP drive back in set the Vista drive as the default boot device using that as the host boot drive.

You then copy XP's boot files over to it. Following the edit of the boot.ini file pointing to the XP drive you simply add the option to boot XP into the Vista boot loader. You end up seeing both drives seeing stand alone OSs while still having a working dual boot instead going into the bios boot order or pressing the assigned F key to bring up the boot device menu for a one time session.