Inside the Dell PC Restore Partition
An Exploration by
Restoring Dell's MBR Boot Code
Dell uses customized boot code that diverts the boot process to the 'DB'
partition when Ctrl+F11 is pressed. This boot
code can easily be overwritten by other, non-Dell applications.
Note that although the Dell MBR is specific to Dell, it is
not specific to the machine or model.
It makes no difference which Dell model you have, how your hard disk is
partitioned, or which operating system you are running.
To restore the Dell MBR boot code, you must first obtain a copy of the
Copyright laws prevent me from making a copy of the Dell MBR available
for download, but if you have another recent Dell desktop or laptop,
you probably already have your own copy of the Dell MBR.
Then it's just a matter of saving a backup of the MBR from the source disk
and restoring the backup to the target disk.
There are many utilities around that can save and restore the MBR, although
most seem to restore the entire MBR sector, not just the boot code portion.
I have included with dsrfix.zip my utility, MBRsaver (mbrsaver.com), which
has been specially designed to allow you to restore just the boot code portion
of the MBR sector.
(Note: Type "mbrsaver"
without any options to get a syntax help screen.)
MBR backup tools save an entire sector (512 bytes), which contains not only
the boot code, but an NT Serial Number (aka, Disk ID) and a partition table.
You do not want to overwrite your partition table!
The partition table that is part of the MBR backup from another machine
almost certainly won't match your own partition table. The partition table
is the index to your hard disk's partitions. Overwriting this index with a
mismatched copy from another computer may render some or all of your
partitions unreadable. The purpose of copying the MBR from another machine
is to restore your boot code, not your partition table.
To use MBRsaver, follow these steps:
- Note: To save a backup file, you must have a writable location
on which to save. This will typically be a floppy disk or USB flash drive.
MBRsaver cannot save your backup file to a CD.
In the instructions below, you will need to use the appropriate drive letter
in the MBRsaver commands.
- Begin with your computer with a known working Dell MBR. (If your
computer briefly displays the blue "www.dell.com" bar at the top of
the screen during bootup, it has a working Dell MBR.)
- Boot the source computer from a DOS boot disk and run the command
"mbrsaver /s a:\dellmbr.bin"
to save the MBR sector.
- Move to your computer on which the Dell MBR needs to be restored.
- Boot the target computer from a DOS boot disk and run the command
"mbrsaver /s a:\backup.bin"
to save the MBR sector. This backup copy is optional, but will allow you to
recover if something should go wrong while you are tinkering with the MBR.
- Run the command
"mbrsaver /r a:\dellmbr.bin".
This will restore your MBR sector from dellmbr.bin--the MBR saved from
the other machine. You will be given a choice of which of the three parts
of the sector you want to restore: the boot code, the Disk ID, and/or the
partition table. Do not overwrite your partition table!
Normally, you should not need to overwrite your Disk ID, either.
So answer 'yes', 'no', 'no' to MBRsaver's three prompts, then confirm your
choices by answering 'yes' to the final prompt.
If you use an alternative tool instead of MBRsaver, you should be able to
follow the same general procedure. Just make sure you don't lose your own