3–24
376220-001
Service Reference Guide, dc5100
Desktop Management
3.4.6 Master Boot Record Security
The Master Boot Record (MBR) contains information needed to successfully boot from a disk
and to access the data stored on the disk. Master Boot Record Security may prevent unintentional
or malicious changes to the MBR, such as those caused by some computer viruses or by the
incorrect use of certain disk utilities. It also allows you to recover the “last known good” MBR,
should changes to the MBR be detected when the system is restarted.
To enable MBR Security, complete the following steps:
1. Turn on or restart the computer. If you are in Windows, click
Start > Shut Down > Restart.
2. As soon as the computer is turned on, press and hold the
F10
key until you enter Computer
Setup. Press
Enter
to bypass the title screen, if necessary.
✎
If you do not press the
F10
key at the appropriate time, you must restart the computer and press
and hold the
F10
key again to access the utility.
If you are using a PS/2 keyboard, you may see a Keyboard Error message—disregard it.
3. Select
Security > Master Boot Record Security > Enabled.
4. Select
Security > Save Master Boot Record.
5. Before exiting, select
File > Save Changes and Exit.
When MBR Security is enabled, the BIOS prevents any changes being made to the MBR of the
current bootable disk while in MS-DOS or Windows Safe Mode.
✎
Most operating systems control access to the MBR of the current bootable disk; the BIOS cannot
prevent changes that may occur while the operating system is running.
Each time the computer is turned on or restarted, the BIOS compares the MBR of the current
bootable disk to the previously saved MBR. If changes are detected and if the current bootable
disk is the same disk from which the MBR was previously saved, the following message is
displayed:
1999—Master Boot Record has changed.
Press any key to enter Setup to configure MBR Security.
Upon entering Computer Setup, you must
■
Save the MBR of the current bootable disk;
■
Restore the previously saved MBR; or
■
Disable the MBR Security feature.
You must know the setup password, if one exists.
If changes are detected and if the current bootable disk is
not
the same disk from which the MBR
was previously saved, the following message is displayed:
2000—Master Boot Record Hard Drive has changed.
Press any key to enter Setup to configure MBR Security.
Upon entering Computer Setup, you must
■
Save the MBR of the current bootable disk; or
■
Disable the MBR Security feature.
