WM_APCSYSMSG_BACKUPNOTIFY

This message notifies an application that it should flush all its data and prepare for backup of the file system, object store and registry.

Parameters

wParam

Specifies the thread identifier of the Backup.exe received by an application, or 0 when posted by the application to Backup.exe.

lParam

Specifies the backup transaction identifier.

Remarks

The Backup.exe broadcasts this message at the beginning of the backup operation. Applications should flush their data to the registry, file system, or object store upon receiving this message to ensure that the data is preserved by the backup operation. Applications which have opened data files with the DENY_READ attribute set should close the files if the files should be backed up. Applications have five seconds after this message is sent to complete their save operations. Any application may request more time in units of five seconds by posting this message to the backup thread by setting wParam to 0.

If an application has a data file open, it may wish to close the file on receiving this message so the file will be backed up.