This per-machine system policy is used only if logging has not been enabled by the "/L" command line option or by MsiEnableLog. If the policy is set in this case, the installer creates a log file in %temp% with the random name: MSI*.LOG. Specify the logging mode by setting the policy value to a string of characters. Use the same characters to specify logging mode policy as used by the "/L" command line option. Note that you cannot use "+" and "*" for the policy.
The logging mode can be set using policy, a command line option, or programmatically. For more information about all the methods that are available for setting the logging mode, see Normal Logging in the Windows Installer Logging section.
You can prevent confidential information, for example passwords, from being entered into the log file and made visible. For more information, see Preventing Confidential Information from Being Written into the Log File
Set the value named Logging under the following registry key.