Ed H said in news:
[email protected]:
Sorry if this off topic, I can't seem to get an answer from Symantec.
Was dual booting XP and XP, tried to format and re-install one, after
the first re-boot got a message something about MBR messed up. Tried
to boot again, got a blue screen error, crashed. Cleaned everything
up, tried it again, uninstalling Boot Magic first, still no go.The
only way to get rid of the error was to format both OS's and
re-install both. How can I resolve this for future use? If I want to
change an OS for another how do I keep Boot Magic from messing up my
MBR? And do you know a good link to explain the boot process? Where
are these files stored?
Thank you,
There are 2 boot programs, one for a hardware boot (after the BIOS POST)
and another for the OS boot. The bootstrap program is in the first 460
bytes of sector 0 of the first physcially scanned hard disk found by the
BIOS. The BIOS loads this bootstrap code. The standard bootstrap
program reads the partition table to find out which partition is marked
as active. It then reads the partition table entry for the active
partition to find out its starting sector. The bootstrap program then
loads the boot program found in the boot sector (first one in that
active-marked partition) which is the actual first file opened for the
operating system. The BIOS loads and starts the bootstrap program in
the MBR (first 460 bytes of sector 0 of 1st physical hard disk) which
then loads and starts the boot program in the first sector of the
active-marked partition.
BootMagic does a little to change this but not by much. It replaces the
standard bootstrap code in the MBR but the rest of BootMagic must reside
on a FAT partition. That is, BootMagic is larger than will fit within
the 460 bytes allocated for the bootstrap code in the MBR, so
BootMagic's bootstrap program merely knows where the rest of its program
files reside and loads those. Other boot managers will sometimes usurp
the unused remaining portion of track 0 for their additional program
code and/or to extend the partition table beyond its 4-entry limit (so
you can boot dozens of operating systems) whereas BootMagic keeps all
that data on whatever FAT partition where it was installed.
Parallel installs of various Windows versions should not touch the MBR
bootstrap area (unless there is no bootstrap program there). The
conflict arises in them vying for use of the boot sector in the
partition in which that operating system was installed. You install
Windows XP into a partition and it writes its boot program into the
first sector of that partition. You then install Windows ME and it,
too, writes its boot program into the first sector of its partition. If
you install Windows ME into the same partition as where you installed
Windows XP, the boot program for Windows ME will overwrite the boot
program that was there before for Windows XP. If you use wholly
separate primary partitions into which you install Windows XP and
Windows ME, each will have their own boot sector in their own partition
and they won't step on each other. Unless there was no MBR bootstrap
program, neither install should overwrite what is there (notice I say
"should").
If you get an MBR bootstrap program you don't want, you can rewrite it.
If you want the Windows XP version of the bootstrap program in the MBR,
boot using the Windows XP install CD, select the first Repair option
which loads the Recovery Console into a ramdisk, and run FIXMBR. If you
want the Windows 9x/ME version of the MBR bootstrap program then boot
using a bootable floppy that has FDISK on it and run "FDISK /MBR".
However, although there my be byte differences between these bootstrap
program versions, I suspect they are near equivalents to each other (I
don't have copies of each to do a compare on their bytes). In fact,
some MBR utilities have an option to overwrite the 460-byte MBR
bootstrap area with a "standard bootstrap program" (don't remember if it
was MBRtool, MBRwork, or MBRwizard).
Rather than uninstall BootMagic, I believe it has an option or program
that will restore the original MBR bootstrap code (or maybe it just
installs what is considered the "standard bootstrap program"). But then
FIXMBR or FDISK /MBR would probably do the same thing. You give so
little information regarding what actually happened that it is
impossible to provide details on how to prevent the same problem(s) from
arising again. Your description is way too vague to provide
preventative remedies but then unless you are familiar with the MBR, how
the system boots, the partition table, and boot programs for the various
Windows flavors then it gets really hard to remember what all happened
(unless you keep a writing pad and pen next to your computer to write it
all down).
