Changing Driver Loading Controls in the Registry

Under most circumstances, you should define the startup behavior of a device or a service by using the Devices option or the Services option in Control Panel, or by using Server Manager under Windows NT Server. Use these methods in specific cases where you cannot define behavior by using the other administrative tools.

You can change the basic value entries in the Registry to control driver loading for a specific driver. For example, you can change:

At what point the driver is loaded or the service is started, including turning off driver loading during startup.

The load order for a driver, a service, or a group during system startup.

Error control for a driver or service, so that startup continues or halts depending on whether the item is initialized.

Parameters that can be set for a driver or service.

To change the behavior of a driver or service

1. Select the subkey for the driver or service in the following Registry path:

HKEY_LOCAL_MACHINE\System
\CurrentControlSet
\Services
\DriverName

2. If you want to change how system startup proceeds if the driver is not loaded or the service is not started, change the value of ErrorControl as follows:

Value	Meaning

0x3	Critical. Fail the attempted system startup.
0x2	Severe. Switch to LastKnownGood or, if already using LastKnownGood, continue in case of error.
0x1	Normal. Continue startup if the driver fails to load, but display a message noting the failure.
0x0	Ignore.

3. If you want to change the dependencies for loading the service, specify new values for the DependOnGroup, DependOnService, or Tag value entry.

4. If you want to change when the service is started or the driver is loaded, change the Start value as follows:

Value	Start type	Meaning

0x0	Boot	Loaded by the Boot Loader.
0x1	System	Loaded at Kernel initialization.
0x2	Auto load	Loaded or started automatically at startup.
0x3	Load on demand	Available, but started only by the user.
0x4	Disabled	Do not start.

5. To put these values into effect, close Registry Editor, then shut down and restart the computer.

For details about Start and ErrorControl values, see their definitions in Regentry.hlp, the Registry Help file on the Windows NT Workstation Resource Kit CD.