Windows XP Hacks [Electronic resources] نسخه متنی

Hack 94 Repair and Recovery with the Recovery Console

If Windows won't start, use
the DOS-like Recovery Console to make repairs.

The Recovery Console is one of the
last-ditch tools you can use if your Windows installation
doesn't start up at all. Before you resort to the
Recovery Console, if Windows starts up, make sure
you've already tried System Restore (especially if
you've recently changed your hardware).

To run System Restore, choose Control Panel Performance
and Maintenance System Restore.

If it won't start, try running the Windows XP Setup
Wizard from the installation CD and choosing its Repair option, or
try starting Windows in Safe Mode.

If none of these easier paths work, you're stuck
using the DOS-like Recovery Console to figure out
what's wrong with Windows, your system or boot
partition, or your disk's master boot record (MBR).
You can use its DOS-like commands to look at the files and folders
that make up Windows, and possibly repair them. You can also repair
the master boot record and boot sector.

You can configure the Recovery Console not to require the
administrator password on login. In the Registry Editor [Hack #68], set
the value of key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion
\Setup\RecoveryConsole\SecurityLevel
to 1.

11.5.1 Starting the Recovery Console

To start
the Recovery Console, boot your computer from the Windows XP
installation CD and follow the prompts. When it asks which Windows
installation you want, type the number of the installation
(1, if Windows XP is the only operating system
installed) and press Enter. Type the password for the Administrator
account. When the Recovery Console is running, you see the prompt
D:\WINDOWS>, which tells you the name of the
current folder (directory).

If you plan to use the Recovery Console often, add it to your boot menu (the menu that appears if you have a multiboot system). You must be logged in as an administrator. Choose Start Run and type the command d:\i386\winnt32.exe /cmdcons (replace d: with your CD drive's letter if it's not D). The Recovery Console occupies about 7 MB of disk space and stores its program files in \Comdcons on your system drive.

Now you can type commands and press Enter, just like in the good old
days of DOS! However, not all DOS commands work (see Section 11.5.5 at the end of this hack),
and you can't examine files in all folders. You are
restricted to the Windows program folder
(C:\Windows on most systems), its subfolders,
the root folder of the Windows partition (C:\ on
most systems), removable drives (including diskette, ZIP, and CD
drivesbut these are read-only), and the
\Cmdcons folder (which contains the Recovery
Console program itself, if you have added it to your boot menu).

If you know DOS, the Recovery Console's commands
look familiar, though only a few are available and some work
differently. To see a list of all the available commands, type
help and press Enter. To find out how a specific
command works, type the command, followed by a space and
/? (for example, expand /?).
When you are done using the Recovery Console, type
exit and press Enter to reboot your
computer.

11.5.2 Looking Around

Use these commands to
examine your system:

cd folder

Changes the current folder to the folder you name. In the folder
name, two dots (..) represents the parent folder of the current
folder. To move to a different drive, type its drive letter and a
colon and press Enter.

dir folder or dir filename

Lists the contents of the folder, including files and subfolders. For
the filename, you can use * as a wildcard character (for example,
dir *.dll). You see the last modification date and
time, attributes, size (in bytes) and filename. The attributes are
represented by letters: d (directory or folder),
h (hidden), s (system),
e (encrypted), r (read-only),
a (changed since last backup), and
c (compressed).

map

Lists the drive letters with their file format (FAT32 or NTFS), size,
and pathname.

type filename

Displays the contents of the file as text. For executable, graphic,
and other nontext files, you see garbage.

If a filename or pathname includes spaces, enclose it in double
quotes.

11.5.3 Fixing the MBR, Boot Sector, or Boot Menu

If your system
can't find a partition from which to boot, try
fixing the MBR.
Type fixmbr to rewrite the MBR on the boot
partition (the drive or partition from which the computer starts up).

If the system finds the boot partition but the Windows
boot
sector is fouled up on the Windows partition (the drive or partition
where Windows is installed), rewrite the Windows boot sector by
typing fixboot. To specify which drive is the
Windows partition, you can add the drive letter (e.g.,
fixboot c:).

Windows XP includes a boot menu that allows you to choose which
operating system to start up. (It doesn't appear if
your system has only one operating system.) To fix the boot menu, use
the bootscan command. Type bootcfg
/scan to look at all your partitions and drives, scanning
for Windows installations. Type bootcfg /list to list the entries in
boot.ini (the file that contains your boot menu
entries).

11.5.4 Fixing Windows

If something is
wrong with your Windows installation, use these commands to modify or
replace the problematic files:

attrib filename flag

Changes the attribute of a file
(filename). The
flag is + (adds, or
turns on) or - (removes, or turns off), followed by
r (read-only), s (system), or
h (hidden).

chkdsk drive

Checks and repairs files and folders on
drive. Add the /p
switch to check the drive even if no problems are marked.

copy sourcepath1 sourcepath2

Copies the file from sourcepath1
and names the new file
sourcepath2. The asterisk wildcard
(*) doesn't work, so you can copy
only one file at a time.

diskpart

Lets you add or delete partitions, though you can't
resize or move them. (For that, you need a program like
PartitionMagic; go to http://www.partitionmagic.com.)

expand pathname

Decompresses files from a .cab file and puts the
result in the current folder. If the .cab file
contains more than one file, add /f:* to extract
all the files. Or add /f:* /d to list all the
files in the .cab, and then use
expand pathname
/f:filename command to
extract just the one you want.

11.5.5 Hacking the Hack

By default, the Recovery Console
doesn't allow you to use wildcards, copy files from
local drives to removable media, or use the cd
command to list files in subfolders in all folders on all local
disks. It also issues a warning message every time you copy files
that overwrite existing files.

However, if you have the Professional Edition, you can change that
behavior using the Group Policy Editor. At a command prompt, type
gpedit.msc to run the Group
Policy Editor. Go to Local Computer
Policy\Computer Configuration\Windows
Settings\Security Settings\Local Policies\Security Options.
In the list of policies on the right, double-click on
"Recover console: Allow floppy copy and access to
all drives and all folders." Select the Enabled
option and click OK.

Doing this won't actually make the changes; at this
point, you'll have to use the Recovery Console
itself to do that. Open the Recovery Console and use the following
commands to customize its behavior:

set allowwildcards = true

This command lets
you use the * and ? wildcards
with the Recovery Console commands.

set allowallpaths = true

This command lets you use the cd

command to list all files and subfolders
on all folders on all local disks.

set allowremovablemedia = true

This command lets you copy files from local drives to
removable media.

set nocopyprompt = true

This command lets you copy files that overwrite existing files,
without getting a warning prompt.

Margaret Levine Young