Updating Driver Files

Drivers are updated whenever one of the following occurs:

• The Hardware Update Wizard is run from Device Manager.

  Note  Starting with Windows Vista, this wizard is now named the Update Driver Software Wizard.

• Windows Update is run.

• Installation software for a device is run.

• Starting with Windows Vista, you can run the PnPUtil tool from an elevated command prompt to install or update the driver package for the device.

Use the following guidelines when you write installation software and INF files that update existing drivers.

• Installation software can call UpdateDriverForPlugAndPlayDevices, supplying an INF file and a hardware ID, to update drivers for devices that match the hardware ID.

  Starting with Windows Vista, installation software can also call one of the following to update drivers:

  • DiInstallDriver, which pre-installs a driver and then installs the driver on devices present in the system that the driver supports.
  • DiInstallDevice, which installs a specified driver from the driver store on a specified device that is present in the system.

  For more information, see Writing a Device Installation Application.

• When upgrading a driver, class installers and co-installers should not supply finish-install pages in response to DIF_NEWDEVICEWIZARD_FINISHINSTALL unless absolutely necessary. If possible, obtain finish-install information from the settings of the previous installation.

• To the extent possible, class installers and co-installers should avoid basing behavior on whether they are providing an initial installation or are updating drivers for an already-installed device.

• Starting with Windows XP, the registry values CoInstallers32 and EnumPropPages32 are deleted before the delivery of DIF_REGISTER_COINSTALLERS. INF files for earlier operating system versions must explicitly either delete these values or perform a nonappending modify operation on them.

• Starting with Windows XP, the registry values UpperFilters and LowerFilters are deleted before the delivery of DIF_INSTALLDEVICE. INF files for earlier operating system versions must explicitly either delete these values or perform a nonappending modify operation on them.

• Do not use INF DelFiles directives or INF RenFiles directives when updating drivers. Windows cannot guarantee that a particular file is not being used by another device. (Class installers and co-installers can delete or rename files, if they can reliably determine that no devices are using the files.)

• Use the INF DelReg directive to remove old device-specific registry entries from a previous installation of the device, if the entries are no longer needed. (Do not remove global registry entries.)

• Do not use the INF DelService directive in an INF DDInstall.Services section to remove previously installed device/driver services from the target computer. Windows cannot guarantee that a particular service is not being used by another device. (Class installers and co-installers can delete services, if they can reliably determine that no devices are using the services.)

• When updating a class installer, class co-installer, or service DLL, you must give the new version a new file name.

For more information about INF files, see Creating an INF File and INF File Sections and Directives.