I hope this is the correct section to post this.

I've just installed the latest Windows updates and I checked the Malicious Software Removal tool log. In scrolling through the log, I've only just realized that this tool is running periodically throughout the day. The time intervals vary. Is this normal? I thought this tool only ran after you downloaded the update from Windows.

The entries just show the tool starts and finishes. The return code is 0. When it is updated and the computer restarted, the entry for that says "no infection found".

I'm running ESET Smart Security, and I use Hitman Pro and Malwarebytes as on-demand scanners.