ChangeServiceConfig info  Overview  Group

The ChangeServiceConfig function changes the configuration parameters of a service.

BOOL ChangeServiceConfig(

Parameters

hService

Identifies the service. This handle is returned by the OpenService or CreateService function and must have SERVICE_CHANGE_CONFIG access.

dwServiceType

A set of bit flags that specify the type of service. Specify SERVICE_NO_CHANGE if you are not changing the existing service type; otherwise, specify one of the following flags to indicate the service type.

Value	Meaning
SERVICE_WIN32_OWN_PROCESS	Specifies a Win32-based service that runs in its own process.
SERVICE_WIN32_SHARE_PROCESS	Specifies a Win32-based service that shares a process with other services.
SERVICE_KERNEL_DRIVER	Specifies a driver service.
SERVICE_FILE_SYSTEM_DRIVER	Specifies a file system driver service.

If you specify either SERVICE_WIN32_OWN_PROCESS or SERVICE_WIN32_SHARE_PROCESS, you can also specify the following flag.

dwStartType

Specifies when to start the service. Specify SERVICE_NO_CHANGE if you are not changing the existing start type; otherwise, specify one of the following flags to indicate the start type.

Value	Meaning
SERVICE_BOOT_START	Specifies a device driver started by the operating system loader. This value is valid only for driver services.
SERVICE_SYSTEM_START	Specifies a device driver started by the IoInitSystem function. This value is valid only for driver services.
SERVICE_AUTO_START	Specifies a service to be started automatically by the service control manager during system startup.
SERVICE_DEMAND_START	Specifies a service to be started by the service control manager when a process calls the StartService function.
SERVICE_DISABLED	Specifies a service that can no longer be started.

dwErrorControl

Specifies the severity of the error if this service fails to start during startup, and determines the action taken by the startup program if failure occurs. Specify SERVICE_NO_CHANGE if you are not changing the existing error control; otherwise, specify one of the following flags to indicate the error control.

Value	Meaning
SERVICE_ERROR_IGNORE	The startup program logs the error but continues the startup operation.
SERVICE_ERROR_NORMAL	The startup program logs the error and puts up a message box pop-up but continues the startup operation.
SERVICE_ERROR_SEVERE	The startup program logs the error. If the last-known-good configuration is being started, the startup operation continues. Otherwise, the system is restarted with the last-known-good configuration.
SERVICE_ERROR_CRITICAL	The startup program logs the error, if possible. If the last-known-good configuration is being started, the startup operation fails. Otherwise, the system is restarted with the last-known good configuration.

lpBinaryPathName

Pointer to a null-terminated string that contains the fully qualified path to the service binary file. Specify NULL if you are not changing the existing path.

lpLoadOrderGroup

Pointer to a null-terminated string that names the load ordering group of which this service is a member. Specify NULL if you are not changing the existing group. Specify an empty string if the service does not belong to a group.

lpdwTagId

Pointer to a DWORD variable that receives a tag value that is unique in the group specified in the lpLoadOrderGroup parameter. Specify NULL if you are not changing the existing tag.

You can use a tag for ordering service startup within a load ordering group by specifying a tag order vector in the GroupOrderList value of the following registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control 

Tags are only evaluated for driver services that have SERVICE_BOOT_START or SERVICE_SYSTEM_START start types.

lpDependencies

Pointer to a double null-terminated array of null-separated names of services or load ordering groups that the system must start before this service can be started. (Dependency on a group means that this service can run if at least one member of the group is running after an attempt to start all members of the group.) Specify NULL if you are not changing the existing dependencies. Specify an empty string if the service has no dependencies.

You must prefix group names with SC_GROUP_IDENTIFIER so that they can be distinguished from a service name, because services and service groups share the same name space.

lpServiceStartName

Pointer to a null-terminated string that names the service. Specify NULL if you are not changing the existing name. If the service type is SERVICE_WIN32_OWN_PROCESS, use an account name in the form DomainName\UserName. The service process will be logged on as this user. If the account belongs to the built-in domain, you can specify .\UserName. If the service type is SERVICE_WIN32_SHARE_PROCESS you must specify the LocalSystem account.

If the service type is SERVICE_KERNEL_DRIVER or SERVICE_FILE_SYSTEM_DRIVER, the name is the driver object name that the system uses to load the device driver. Specify NULL if the driver is to use a default object name created by the I/O system.

lpPassword

Pointer to a null-terminated string that contains the password to the account name specified by the lpServiceStartName parameter. Specify NULL if you are not changing the password. Specify an empty string if the service has no password.

Passwords are ignored for driver services.

lpDisplayName

Pointer to a null-terminated string that is to be used by applications to identify the service for its users. This string has a maximum length of 256 characters. The name is case-preserved in the service control manager. Display name comparisons are always case-insensitive.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Errors

The following error codes may be set by the service control manager. Other error codes may be set by the registry functions that are called by the service control manager.

Remarks

The ChangeServiceConfig function changes the configuration information for the specified service in the service control manager database. You can obtain the current configuration information by using the QueryServiceConfig function.

If the configuration is changed for a service that is running, with the exception of lpDisplayName, the changes do not take effect until the service is stopped.

The startup program uses load ordering groups to load groups of services in a specified order with respect to the other groups in the list. The list of load ordering groups is contained in the ServiceGroupOrder value of the following registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control 

See Also

CreateService, OpenService, QueryServiceConfig, StartService

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