The article contains REGISTRY entries for the CurrentControlSet\Control
Subkeys Part 1. These subkeys are included:
- BootVerificationProgram
- ComputerName
- DisplayDriver
- GroupOrderList
- HiveList
- KeyboardLayout
- Lsa
- NetworkProvider
- Nls
- PriorityControl
- ProductOptions
- ServiceGroupOrder
For listings of the other control subkeys under CurrentControlSet, see the
articles:
CurrentControlSet Part 2: SessionManager Entries, and CurrentControlSet
Part 3, which contains entries for:
- Setup
- TimeZoneInformation
- VirtualDeviceDrivers
- Windows
- WOW
CURRENTCONTROLSET\CONTROL SUBKEYS ENTRIES
This key contains parameters that control system startup, such as
subsystems to load, the size and location of paging files, and so on.
NOTE: The system must be restarted for any changes in the Control key to
take effect.
The Control subkey itself can contain the following value entries:
Current User REG_SZ Username
Default: Username
Specifies the username for the currently logged-on user.
RegistrySizeLimit REG_DWORD Size in bytes
Default: 8 MB (That is, 25 percent of the default PagedPoolSize.)
Specifies the total amount of space that can be consumed by Registry data.
The system ensures that the value for RegistrySizeLimit is at least 4MB and
no greater than about 80 percent of the size of PagedPoolSize. Setting
RegistrySizeLimit to 0xffffffff sets the value to be as large as 80 percent
of PagedPoolSize (under the Control\Session Manager\MemoryManagement key).
You can allow for a bigger Registry by setting the initial PagedPoolSize,
or you can set the value of RegistrySizeLimit. If you want a very large
Registry, set both. However, for all but a few domain controllers,
RegistrySizeLimit never needs to be changed.
RegistrySizeLimit must have a type of REG_DWORD and a data length of 4
bytes, or it will be ignored.
SystemStartOptions REG_SZ String
Contains the text of system arguments passed to the system by the firmware.
These values can be used to determine whether the debugger is enabled, the
options set for ports and speed, and so on. For example, the following
value could be defined for SystemStartOptions:
c:\winnt="Windows NT" /DebugPort=com1/DebugBaudRate=56000
In this example, "Windows NT" in the first part of the string indicates the
SystemRoot specified under the Windows NT\CurrentVersion subkey in the
Software area of the Registry. The remaining portion of this string is
interpreted by the system to define the COM port and baud rate for
debugging.
The following standard Control subkeys are found under this Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
Their values (where appropriate--some marked in the list below should not
be edited by users) are located in these files:
BootVerificationProgram, ComputerName, DisplayDriver, GroupOrderList,
Hivelist, Keyboard Layout, Lsa, NetworkProvider, Nls, PriorityControl,
ProductOptions and ServiceGroupOrder control entries are listed in the
remainder of this file, following the list below.
SessionManager entries are in the article "CurrentControlSet, Part 2:
SessionManager Entries."
Setup, TimeZoneInformation, VirtualDevice, WindowsStartup and WOW entries
are in the article "CurrentControlSet, Part 3."
Here is a complete list of Control Subkeys:
Boot Verification Program
ComputerName (These keys contain information used only by the system and
should not be edited by users. Because these entries should be maintained
only by the system, they are not described in these files.)
DisplayDriverControl (These keys contain information used only by the
system and should not be edited by users. Because these entries should be
maintained only by the system, they are not described in these files.)
GroupOrderList
ServiceGroupOrder
HiveList
KeyboardLayout
Lsa (These keys contain information used only by the system and should not
be edited by users. Because these entries should be maintained only by the
system, they are not described in these files.)
NetworkProvider
Nls
Print (See the article "Registry Entries for Printing.")
PriorityControl (These keys contain information used only by the system and
should not be edited by users. Because these entries should be maintained
only by the system, they are not described in these files.)
ProductOptions (These keys contain information used only by the system and
should not be edited by users. Because these entries should be maintained
only by the system, they are not described in these files.)
SessionManager
Setup (These keys contain information used only by the system and should
not be edited by users. Because these entries should be maintained only by
the system, they are not described in these files.)
TimeZoneInformation (These keys contain information used only by the system
and should not be edited by users. Because these entries should be
maintained only by the system, they are not described in these files.)
VirtualDeviceDrivers
Windows
WOW
BootVerificationProgram Control Entries
The BootVerificationProgram key is used to update the last known good
configuration during system startup. This entry describes a program that
will be called by the service controller to establish the last known good
configuration. Such a program can be written by the system administrator.
The Registry path for this key is the following:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Control\BootVerificationProgram
Any entry added under this subkey must have the following format:
ImagePath Reg_SZ or REG_EXPAND_SZ Filename
Default: (no entry)
Specifies the filename for a startup verification program.
You must also specify a value of 1 for the ReportBootOK entry under the
following Registry path:
HKEY_LOCAL_MACHINE\Software\Windows NT\CurrentVersion\WinLogon
When the value of ReportBootOK is set to 0, it disables the automatic
(default) startup acceptance, which happens after the first successful
logon.
As an alternative, if you want to verify system startup from a remote
location, the BootVerification service supplied with Windows NT can be used
instead of the BootVerificationProgram, as described later in this chapter.
The BootVerification service cannot be used in conjunction with entries in
the BootVerificationProgram subkey.
NOTE: Do not change values in the BootVerificationProgram key unless you
need a custom verification program to satisfy specific startup criteria at
your site. Otherwise, accept the default procedures for verifying system
startup.
ComputerName Control Entries
The ComputerName key contains the system's computername.
CAUTION: Do not change the ComputerName values in the Registry. The
computername should be changed only by choosing the Network icon in Control
Panel or by applications using the Get/SetComputerName APIs.
There are two subkeys under ComputerName:
ActiveComputerName and ComputerName. This is because a new computername
takes effect only on the next system startup. Changing the computername
changes the value in the ComputerName key. When you start the system, the
ComputerName key gets copied to the ActiveComputerName key (which is
volatile and which provides the computername during that session). These
two subkeys appear under the following Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName
These two subkeys each contain a value entry of the following type:
ComputerName REG_SZ ComputerName
Default: ComputerName defined during Setup
Defines the name for the computer as identified for network browsers.
DisplayDriverControl Entries
Entries under the following Registry path define basic display driver
information used during system startup:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DisplayDriverControl
DriverEnabled REG_DWORD 0 or 1
Default: 0
LayeredDriver REG_SZ String
Default: layrdisp
MaxClientCount REG_DWORD Number
Default: 0x4
These entries should be maintained only by the system.
GroupOrderList Control Entries
The entries in the GroupOrderList key specify the ordering of services
within groups, under the following Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GroupOrderList
For a service listed under CurrentControlSet\Services, the value of the
Group entry plus any Tag entry determines the order in which the service is
loaded. But not all services have a Tag entry, and not all groups have an
entry in the GroupOrderList subkey. The ServiceGroupOrder subkey described
later in this article specifies the order for loading groups. The entries
in the key are all of type REG_BINARY. These default entries define the
order within groups:
Base Pointer Class Video
Ndis SCSI Miniport Keyboard Port
Primary Disk Keyboard Class
Filter Pointer Port
HiveList Control Entries
The location of the files that contain Registry information is reported
under the following Registry path:
HKEY_CURRENT_MACHINE\SYSTEM\CurrentControlSet\Control\hivelist
All data types are REG_SZ. The following are the default entries:
\REGISTRY\MACHINE\HARDWARE
\REGISTRY\MACHINE\SAM=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\SAM
\REGISTRY\MACHINE\SECURITY=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\SECURITY
\REGISTRY\MACHINE\SOFTWARE=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\SOFTWARE
\REGISTRY\MACHINE\SYSTEM=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\SYSTEM
\REGISTRY\USER\.DEFAULT=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\DEFAULT
\REGISTRY\USER\SID_#=
\Device\Harddisk0\Partition1\SystemRoot\SYSTEM32\CONFIG\ADMIN000
Keyboard Layout Control Entries
The Keyboard Layout key maintains the mapping of keyboard layout names to
keyboard layout DLL names, under the Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout
The Keyboard Layout key is used by the system to determine which DLL to
load. The mapping may contain duplicated keyboard layout DLL names if that
DLL implements the layout for more than one language (in other words, a
keyboard layout may have more than one name). Individual preferences are
stored under HKEY_CURRENT_USER\Keyboard Layout.
The Keyboard Layout key contains an entry in this format:
KeyboardLayout REG_SZ DLL filename
By convention, a keyboard layout name is a null-terminated string of 8
hexadecimal digits representing a language ID (in the last four digits) and
a variation number (in the first four digits).
For example, the language ID of Swiss German is 0x807, so, by convention,
keyboard layout names could be 00000807, 00010807, and so on.
The DosKeybCodes subkey is used by the system to convert Windows NT
keyboard layout names into MS-DOS-style two-character keyboard layout names
as used by the kb16 command (equivalent to keyb in MS-DOS). The system must
automatically switch the VDM keyboard layout whenever the Windows NT
keyboard layout is changed. Entries are found under this Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Control\Keyboard Layout\DosKeybCodes
KeyboardLayout REG_SZ Two-character code
These entries define the two-character equivalent for each keyboard layout.
This list summarizes the entries under DosKeybCodes:
00000405=cz 00000414=no 0000080C=be
00000406=dk 00000415=pl 00000813=be
00000407=gr 00000416=br 00000816=po
00000409=us 00000419=ru 00000C0C=cf
0000040A=sp 0000041A=yu 00001009=us
0000040B=su 0000041B=sl 0000100C=sf
0000040C=fr 0000041D=sv 00010409=dv
0000040E=hu 00000807=sg 0001040A=sp
0000040F=us 00000809=uk 00010C0C=cf
00000410=it 0000080A=la 00020409=us
00000413=nl
Lsa Control Entries
The authentication package for the local security authority has values
defined under the following Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
These values should be maintained only by the system-errors may prevent
anyone from being able to log on to the computer.
Authentication Packages REG_MULTI_SZ Filenames
Default: msv1_0
Bounds REG_BINARY
Default: (none)
NetworkProvider Control Entries
Windows NT supports a common interface that allows networks from several
different vendors (that is, network providers) to operate on a single
computer at the same time. The NetworkProvider subkey provides a list of
the available network providers that use the Microsoft network-independent
APIs. The following value for the Order subkey appears under this Registry
path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Control\NetworkProvider\Order
ProviderOrder REG_SZ Comma-separated list of keynames
Default: LanmanWorkstation (when a single network is installed)
Specifies the order for accessing available network providers, as defined
by choosing the Networks button in the Network dialog box in Control Panel.
Each entry in this list is in the form of a Registry Services key name for
a service or driver that is associated with a particular network provider.
The Services subkey associated with a network provider should contain a
Group entry with the value of NetworkProvider, and must also contain a
NetworkProvider subkey with information for the Multiple Provider Router.
For more information, see "NetworkProvider" in the "Registry Entries for
Network Services" section later in this chapter.
Nls Control Entries
This key contains subkeys that define information for languages and code
pages.
In the Code Page and Language subkeys, all code pages and languages
supported under Windows NT are listed, so applications can check these keys
to find all "supported" languages. However, only the entries with filenames
in the data fields are actually installed in the system. So applications
must check the data fields to find out if a specific code page is actually
installed in the system.
Nls Control CodePage Entries
The entries under the following Registry path identify the files for
available code pages. If there is no value following the entry name, that
code page is not installed in the system.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\CodePage
Each entry has the following format:
CodePageID REG_SZ Filename
As shown in the following list, 437=C_437.NLS indicates the file for code
page 437, and 1252=C_1252.NLS indicates the file for code page 1252, and so
on. ACP is the default ANSI code page; OEMCP is the default OEM code page;
and MACCP is the default Macintosh code page.
10000=c_10000.nls 1253= 861=
10006= 1254= 863=
10007= 437=c_437.nls 865=
10029= 500= 866=
1026= 850=c_850.nls 869=
1250= 852= 875=
1251= 855= ACP=1252
1252=c_1252.nls 857= MACCP=10000
860= OEMCP=437
Nls Control Language Entries
The entries under the following Registry path identify the files for
available languages. If there is no value following the entry name, that
language is not installed in the system.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\Language
Each entry has the following format:
LanguageID REG_SZ Filename
As shown in the following table, l_INTL.NLS is the file for language 0409,
l_INTL.NLS is the file for language 0809, and so on.
Default: 0409 (the default language ID)
0405=l_intl.nls 0414= l_intl.nls 0813=l_intl.nls
0406= l_intl.nls 0415=l_intl.nls 0814=l_intl.nls
0407=l_intl.nls 0416=l_intl.nls 0816=l_intl.nls
0408= 0419=l_intl.nls 0c07=l_intl.nls
0409=l_intl.nls 041b=l_intl.nls 28=l_intl.nls
040a=l_intl.nls 041d=l_intl.nls 0c0a=l_intl.nls
040b= l_intl.nls 041f= 0c0c=l_intl.nls
040c=l_intl.nls 0807=l_intl.nls 1009=l_intl.nls
040e=l_intl.nls 0809=l_intl.nls 100c=l_intl.nls
040f=l_intl.nls 080a=l_intl.nls 1409=l_intl.nls
0410=l_intl.nls 080c=l_intl.nls 1809=l_intl.nls
0413=l_intl.nls 0810=l_intl.nls
Nls Control OEMLocale Entries
The following key, if present, can contain entries that an OEM adds to
customize its locale:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\OEMLocale
This section of the Registry is only checked if a specific locale ID is not
found in the default locale file (LOCALE.NLS). If this subkey is present,
each entry has the following format:
OEMlocale REG_SZ filename
Default: This subkey is not present, so there is no default.
Specifies the locale ID and a filename for the OEM locale.
PriorityControl Entries
The PriorityControl key defines the foreground/background priority boost
differential. Change this value by choosing the Tasking button in the
System dialog box in Control Panel. Values are stored under this Registry
path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\PriorityControl
Win32PrioritySeparation REG_DWORD 0, 1, or 2
Default: 0x2
Specifies the priority to give to the application running in the forground.
This application receives more process or time relative to other
applications running in the background. The values here correlate to the
following options in the Tasking dialog box:
Value Meaning
0 Foreground and background applications equally responsive
1 Foreground application more reponsive than background
2 Best foreground application response time
ProductOptions Control Entries
The ProductOptions subkey contains miscellaneous information used by the
system, under the following Registry path:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ProductOptions
The following entry appears under this key.
ProductType REG_SZ Product name
Specifies the installed version of Windows NT as either WinNT (for Windows
NT) or LanmanNT (for Windows NT Advanced Server).
ServiceGroupOrder Control Entries
The ServiceGroupOrder key specifies the order to load various groups of
services.
Order within groups is specified using the value of Tag under the specific
Services subkeys and the values in the GroupOrderList subkey. For example,
when you start Windows NT, the Boot Loader scans the Registry for drivers
with a Start value of 0 (which indicates that these drivers should be
loaded but not initialized before the Kernel) and a Type value of 0x1
(which indicates a Kernel device driver such as a hard disk or other low-
level hardware device driver). The drivers are then loaded into memory in
the order specfied as the List value in the ServiceGroupOrder subkey.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ServiceGroupOrder
List REG_MULTI_SZ Group names
Specifies the order for loading drivers into memory.
Default:
SCSI miniport
port
Primary disk
SCSI class
SCSI CDROM
class filter
boot file system
Base
Keyboard Port
Pointer Port
Keyboard Class
Pointer Class
Video
file system
Event log
Streams Drivers
NDIS
TDI
NetBIOSGroup
NetDDEGroup
extended base network
Reference: "The Windows NT Resource Kit for Operating System Version 3.1".