mettelus
I run Win7 Ultimate, and the biggest offender to latency is Network Auto Discovery (shut that off), close seconds are anything that auto-starts or auto-updates. Running msconfig regularly to check non-Windows processes and startup programs to strip them is advised, since many revert on updates. Running Services and setting about half of the autoruns to "manual" will solve most issues (services will still start but only when you initiate them). This advice is hardware/software load dependent by system, so no set list (but there are several threads that discuss common offenders).

On the latency monitor app, the tabs at the top give insight on what is going on and can sort by columns. The bigger offenders can be Googled to see what they belong to and then disabled (msconfig) or set to manual (Services) in many cases if non-essential. Ones unsure of, can ask here of course.

The other offenders are to disable any power saving features and core parking.

I probably missed a few, but those are the biggies. I have not looked at Win10, so not sure how this differs on that O/S.

Quick edit for the post above this: Yes, you can set to manual or even disable services in Win7. Disabling requires going back into Services to "Start" them again. About 1/3 of my Services are disabled there, but be sure you know they are non-essential before disabling them.

Very helpful list of areas.
As I mentioned, I even started in selective mode, the only thing starting on my computer are:

1. Mouse/Keyboard
2. RME Stuff
3. NVIDIA (something)

I had also disabled all USB ports, leaving only the PCI USB enabled.

But I think you are correct, something was running in the background that I overlooked. Which will explain I got green on the server but red on Windows 7.

Check the other tabs in LatencyMon with SONAR running. Sort through the columns and sort highest to lowest and take screenshots if desired. Those are the ones to research and deal with.

One hidden offender is undo history within SONAR itself. It defaults to 100 and can only be adjusted if you have made an edit to a project. At that point you can look at the undo history and set the record number to a reasonable value (I set mine to 10). In your case this may not do much (your installed RAM), but for others reading this thread, a "RAM challenged" machine will see benefit from knocking down the undo history counts.