I've been noticing a few strange things on my machine. One, the windows update service keeps using up way more RAM than I've seen it use on other similar computers (around 100mb at idle) and after installing my new video card today I saw mrt.exe open in my task manager. should I be concerned?
From everything I can find MRT.exe is from the Microsoft Malicious Software Removal Tool and is built into Windows and is normally patched every now and then to include new malicious software so it should be safe. Weirtd you never saw it before.
As for Windows update, if it is using more RAM than usual it might be downloading updates. Have you checked to see if any are available?
I often disable the BITS service(Background Intelligent Transfer Service) when playing games with extreme penalties for death(ARK for example). My system only has 6GB of tri-channel memory and I often feel ingame penalties for things happening in the OS with memory hog games. Disabling BITS pretty much breaks Windows Updates and can be a pain in the butt to get going again(often requires reboots).