|
|
Initiation responsibility: Head of IT Section, IT Security Management
Implementation responsibility: Administrator, IT users
At the time of the initial installation of an IT system, an emergency floppy disk (or other suitable type of data medium) should be produced which, in case of failure of a hard disk, can be used for starting the system or, in case of virus infection, for generating a controlled system state.
An emergency diskette for a DOS PC should be formatted as a system floppy disk (DOS command FORMAT A: /S ). Subsequently, if sufficient storage space is available, the following programs should be saved on it: the German keyboard driver KEYB.COM as well as KEYBOARD.SYS, COUNTRY.SYS, HIMEM.SYS and the programs FORMAT.EXE, SYS.COM, FDISK.EXE, CHKDSK.EXE, MEM.EXE and DEBUG.EXE.
Appropriate AUTOEXEC.BAT and CONFIG.SYS files should be generated on the floppy disk. These files should provide the usual keyboard layout and DOS prompt. It should be ensured that all path names refer to the floppy disk. Programs must not be loaded from the hard disk (the path names must not contain C:)
The floppy disk should also contain a text editor. The availability of the used backup program must also be ensured. If the storage capacity is exceeded, a second floppy disk can be used. If the hard disk is compressed, an appropriate driver must be found on the emergency floppy disk in order to be able to access the hard disk.
In addition to the operating system files, the emergency floppy disk can also contain auxiliary programs for determining errors and repairing possible defects. It is also an advantage if the files of the system configuration are available. These should be recorded in writing, for example in a PC Checklist Booklet as described in S 2.24 Introduction of a PC Checklist booklet, or be available on data media. For this purpose, there are various programs which read the main configuration data of a PC. Then, if data is interfered with, it can easily be compared to the data saved earlier and corrected if necessary.
The completed emergency floppy disk should be checked for computer viruses using an up-to-data virus scanning program then write protected.
Whenever an operating system is changed (e.g. to a more recent version), a new emergency floppy disk must be created immediately. So that the hard disk can be accessed without problems, the version of the operating system must correspond to the version of the computer concerned. Depending on the operating system, system-specific aspects must also be taken into account (see, for example, S 6.46 Creating an emergency floppy disk for Windows 95 or S 6.42 Creating start-up floppy disks for Windows NT).
If the emergency floppy disk is available to the expert attending to the PCs, this will facilitate his work, especially as regards eradication of computer viruses.
Additional controls:
| © Copyright
by Bundesamt für Sicherheit in der Informationstechnik |
July 1999 |