BOOT.TXT
last update by Roedy Green 2009-03-11

Purpose
*******

BOOTSAVE and BOOTREST protect you in case you accidentally
damage your hard disk master boot sector.  BOOTCHK checks if any
damage has been done.

In the master boot sector is stored the code that gets your
machine going when you first power it on, the partition table of
how big your various partitions are, and in some cases it
contains information about disk geometry (heads, cyls etc).

Protects against damage to the partition table or boot sector
done by rogue programs, viruses or accidents with tools like
Norton NU.  This version does NOT save the boot sectors for each
partition, ust the master boot sector.

The most important thing to remember about BOOTSAVE is that you must
recreate your BOOT.SAV file any time you change you hard disk, or change
your partitions.  Never restore a BOOT.SAV file if you have failed to do
this.  To be safe, redo your BOOT.SAV any time you change your CMOS.  In
theory this should only be necessary if you change the disk settings.

How Do You Use It
*****************

Insert an system DOS-formatted floppy into A: then type:

BootSave A:\Boot.Sav

It will then create a small file called Boot.Sav in the root
directory of your floppy.  This contains 4 bytes of information
about your disk geometry followed by a 512 byte image of your
master boot sector.  The geometry information is used to prevent
you from accidentally restoring the boot track from one machine
onto another machine with a different type of disk.

You may also store this file or hard disk with:

Label the disk with the name of the machine it come from.  If
later you suspect the master boot sector may have been damaged
on contaminated, boot from a floppy and insert a floppy disk
containing the file BootRest.Com and the file Boot.Sav.

Then type

BootRest A:\Boot.Sav

You will then have to reboot before the corrected parameters
take effect.

In your autoexec.bat file you can put:

BootChk C:\CMP\Boot.Sav /Q
If errorlevel 1 GoTo Trouble

To check that the boot sector has not been tampered with.  The
/Q option suppresses all but the most crucial messages.

Why Use It
**********

You may accidentally clobber your boot track of
your C: hard disk which contains the MBR (Master
Boot Record -- the code that is used to start your
computer, and the master partition table which
describes the position and sizes of your four main
hard disk partition).  If you have done a
BootSave, you can have it back in minutes.
Otherwise you will lose the entire contents of
your hard disk.

You may accidentally fool around with FDISK and
wreck your paritions.  BootRest can put the
partition table back the way it was.  This may
rescue your data.

A buggy program might accedintaly overwrite your
boot sector.

A virus might infect your boot sector.  BootRest
will get rid of it.

Windows might destroy your multi-boot to other
operating systems such as Linux.  Bootsave will
easily restore it.

YOU MUST USE REAL DOS
*********************

A DOS box/window/compatibility box/penalty box/command prompt is not the
same as DOS.  It is a DOS emulator part of Windows with many features of
DOS blocked to enhance the security of the computer.  Microsoft rightly
considers meddling with the boot record a potentially dangerous thing to
do, and block programs running in the DOS box from doing it.  For
BOOTsave/BOOTrest, you need real DOS, e.g.  booting from a DOS floppy,
not just the DOS command prompt.

GETTING THE LATEST VERSION
**************************

Look for the latest version at my Web site:
  http://mindprod.com/downloads

Trouble Shooting
****************

> I used BootRest, but it complained the disk geometry was wrong.

You probably did BootSaves from several different computers.
You then failed to label the disks and used a disk from the
wrong computer.  You must use the disk that was done on the
computer you are trying to rescue.  BootRest checks that the
number of heads and sectors etc of the disk you are restoring to
matches the disk the BootSave was done on.

If for some reason the INT 13 is giving the wrong geometry
BECAUSE the boot sector is gibbled, you have a Catch-22
situation.  In that case, you could modify the BootRest code by
putting a semicolon in front of the CALL CHECKGEOM to turn it
into a comment, and reassemble.  This would be dangerous, so I
am not making this easy on purpose.

> I accidentally reformatted by hard disk with FORMAT C: without
> the /S. I used BootRest, but the C: partition was still unbootable,
> and command.com, IO.SYS and MSDOS.SYS were still missing.
> None of my files came back either.  Your stupid program doesn't
> work!

BootRest saves only one tiny 512 byte sector near the start of
your disk.  This is the only thing it can repair.  The current
version does not even save the boot sectors on the front of each
partition.  If you want to make your C: partition bootable
again, use Norton NDD 4.5 or DiskTool 6.0.  You can also try
booting from floppy and typing SYS C:.  To recover from massive
losses of files, there is no subsitute for a tape backup system
with daily backups.

Perhaps in a future version I will save all boot sectors for
each partition.  This job is complicated by the extensions that
SpeedStor and Ontrack Disk Manager make to the partition table.

>I crashed by disk without making a BOOTSAVE file first.  What
>can I do now?

BOOTSAVE is prophylactic.  It is useless for correcting
trouble if you have not used it PRIOR to the trouble. You
may be SOL, but things you can try are: FDISK /MBR and the
Norton Utilities Disk Doctor, which may be able to
recreate damaged boot sector.

Author
******

BOOTSAVE, BOOTREST and BOOTCHK are copyrighted but may be freely
used for any purpose except military.
If you pass the files on, PLEASE PASS ON THIS DOCUMENTATION TOO.

Please report bugs and problems.

Freeware Status
****************

BOOTSAVE BOOTREST and BOOTCHK are freeware.

Roedy Green
Canadian Mind Products
#101 - 2536 Wark Street
Victoria, BC Canada V8T 4G8

tel: (250) 361-9093
mailto:roedyg@mindprod.com
http://mindprod.com

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