The installers of the Invantive products for Microsoft Windows record what they do in log files of their own, beside the log of Windows Installer. The installation window writes a file named after the moment in UTC, the process and the product into the folder `Invantive\Install` of the user profile of the person who installs. Every custom action of the installation writes a file of its own beside it, with the name of the custom action added. A custom action which runs elevated writes into the folder of the person who started the installation, and writes no file when the installation runs under a service account, as with a distribution through software deployment. The files hold one JSON object per line, like a [[Invantive Query Tool/Trace Files|trace file]], and carry the extension `.ndjson` from release 28.0 and the beta release 27.1 before it; earlier releases name the file of the installation window `.log` and write no files for the custom actions. The following environment variables control these logs and are available on Microsoft Windows: - `INVANTIVE_MSI_LOG_TO_FILE`: whether the installer writes its log files into the folder `Install`. Defaults to `true`. - `INVANTIVE_MSI_LOG_TO_SESSION`: whether the installer also writes its messages into the log of Windows Installer, which `msiexec /l*v` produces. Defaults to `true`. - `INVANTIVE_MSI_LOG_ACTIVE`: whether the installer writes its messages to the debug output of Windows, which a tool such as DebugView shows. Defaults to `true`. - `INVANTIVE_MSI_CS_LOG_ACTIVE`: whether the installer sends its most recent messages to [[Customer Service]] along with an error or the end of an installation. Defaults to `true`. - `INVANTIVE_MSI_LOG_IGNORE_EXCEPTIONS`: whether a failure to write a log is ignored instead of stopping the installation. Defaults to `true`. From release 28.0 and the beta release 27.1 the installer also follows the environment variables which switch on the trace of the products. When `INVANTIVE_TRACE_ACTIVE` and `INVANTIVE_TRACE_TO_FILE` are `true` and `INVANTIVE_TRACE_FOLDER` names a folder, every process of the installation writes a trace file into that folder as well, in a subfolder per day (UTC), with the same name and content as the trace files of the products. The name ends in `-writing` while the file is written and in `-c` once it is closed. Without `INVANTIVE_TRACE_FOLDER` no trace file is written, since the installer does not choose a folder of its own. A custom action which runs elevated runs as the local system account and therefore only follows the variables set for the whole device, not those of the person who installs.