The Windows Registry
Adapted from
http://www.j79zlr.com/reg_tutorial.php
http://www.pcsupportadvisor.com/windows_registry_tutorial_page1.htm
• Working with the registry can be
dangerous even if you know what you are
doing.
• Making a wrong change can cause
problems severe enough that they cannot
be solved short of a reinstall.
About
• The Windows XP Registry is a database
repository that is stored on your hard drive.
• This database stores different settings for your
software, hardware, users, and preferences for
Windows itself.
• Ever wonder how Windows remembers your
screen resolution even after you restart your
computer?
– Or how about the size and position of your windows?
– All that is stored in the Registry, and more.
Opening the registry
• This is easy, just click on the start button
and then on run. Once run is open, type in
regedit and click OK.
Hives and Keys
Now you see the "folders"
HKEY_CLASSES_ROOT,
HKEY_CURRENT_USER,
HKEY_LOCAL_MACHINE,
HKEY_USERS, and
HKEY_CURRENT_CONFIG
Some basic terminology
The five main "folders" are
called hives
Their subfolders are called
keys.
Once you open the Registry Editor, you'll notice that it is divided into two
panes. The left pane contains the hives, keys, and sub-keys. The right pane
contains various data types.
The Hives
Backup the entire registry
Click Start
Mouse over All Programs
Mouse over Accessories
Mouse over System Tools
Click Backup
Click Next
Select the Back up files and
settings radio button
Click Next
Select the Let me choose
what to back up radio
button
In the left pane, highlight My
Computer (but don't
check it)
Now in the right pane, check
System State
http://www.puppypc.com/tutorials/reg/backup_xp_reg.htm
Restore Entire Registry If You Can't
Boot Windows
• To restore the Registry when you are unable to boot into
Windows, you will have to use the Last Known Good
configuration by doing the following:
• Press the F8 key while your computer first begins
loading Windows
• In the Windows Advanced Options menu, select Last
Known Good Configuration and press Enter
• Your computer will now boot into Windows with your
most recent settings that worked
Restore the Entire Registry
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Click Next
Select the Restore files and
settings radio button
In the left pane, highlight File
Now, in the right pane, you
should see your backup;
double-click it
If you don't see your backup,
click the Browse... button
System State should now be
displayed in the right pane;
check it
Click Next
Click Finish
Accept the Warning by
clicking OK
You should now see a
Restore Progress window
Once the restoration is
complete, click Close
Click Yes to restart your
computer so the changes will
take effect
Windows XP Home edition
• Windows XP Home edition does not include the
Backup utility by default.
To install it:
• Insert your Windows XP cd
• Open up Windows explorer
• Navigate to ?:\VALUEADD\MSFT\NTBACKUP\
(replace ? with appropriate cd-rom drive letter)
• Double-click NTBACKUP.MSI and follow the onscreen instructions
Keys and values
•
•
if you wanted to open HKEY_CURRENT_USER\Software\Microsoft, click
the + next to Software, then the + next to Microsoft.
Some keys contain other keys and some contain keys and values and some
just contain values
Value Types
• String Values (REG_SZ), which are capable of storing
text or any type of characters (including numbers).
• Binary Values (REG_BINARY) stores information in
binary format but is displayed in hexadecimal format.
• DWORD Values (REG_DWORD), which are used to
store number values. Although displayed in hexadecimal
format, you may enter in data in either hexadecimal or
plain decimal
• Multi-String Values (REG_MULTI_SZ) usually hold data
that contain lists or multiple values in a form.
• EXPandable String Values (REG_EXPAND_SZ)
usually contains variable-length data strings.
“Exporting” keys
•
This should be done to any and all registry keys before changing them.
It will give you an easy way of changing back any changes that you make
editing the registry. Right click the key that you want to eXPort, and select
EXPort.
Exporting /2
• Then give it a
name so you
remember
what it is.
Importing
• Now that you have eXPorted keys to
change back your changes,
you need to know how to import them
into the registry.
Usually a double-click on a registry
file will merge it for you unless you
have changed the default action.
Then you have to right-click the file
and select Merge.
Edit a registry value
Strings /1
• There are three main types of
registry values that you will
deal with: STRINGS,
DWORDS, and BINARY
values.
• There are others, but these are
99% of what you will deal with
doing normal editing.
• To change an existing STRING
value, just double click it and
enter in the new value data.
Hex or Decimal
Dword /2
• To change an existing
DWORD value you have
two options, hexadecimal
and decimal.
• Be sure you know what
type the value should be,
– 200 hexadecimal is 256
decimal,
– c8 is hexadecimal for 200
decimal
Binary /3
• Binary values are
written in hex.
• The applicable
values are entered
the format 00 01 A2
etc
• Changing anything
other than 00 to 01
or 01 to 00 is rare
Adding new registry entries
• Adding values is
very similar to
changing them with
the exception that
you have to name
the value.
• Right click in the lefthand-side of the
registry editor and
select:
• New > String
– (or whatever value
type you want to
add)
Adding a new Key
•
You need to add a key under
HKEY_CURRENT_USER\S
oftware\Policies\Microsoft,
•
Just right-click on
HKEY_CURRENT_USER\S
oftware\Policies\Microsoft in
the folder tree,
and then New > Key
Doing it with Text
Manually /2
Manually /3
Manually /4
Manually /5