Hi Gunther,
I have been using MSE for about 2 months now.
I have experimented with the configuration somewhat, and have for now settled on a default configuration with a small number of excluded file types (source files and similar, but note that I don’t know if these types of files would be scanned even if they were not excluded).
With real-time protection enabled MSE is frequently active, and monopolizing the CPU, during normal use of my system. This is at times somewhat irritating, but this activity does seem to be triggered by just the sort of things that I would expect, and there is the option of turning real-time protection off when necessary. My P3 system all but stops responding while this is going on, probably indicating that MSE is doing something more or less complex, and I think also that it expects to be running on a processor with multiple (physical) cores. Under these same conditions even my 3GHz P4 Northwood system with HT enabled is very slow to respond. In Task Manager the “engine” MsMpEng.exe typically shows ~20 threads.
Microsoft seems to update the definitions at least once per day. The definition updates are automatic, and AFAICT there is no option to control this.
The quick scan seems to run fairly fast. I recently had to rebuild my P3 system, and part of that involved a full scan of a ~15 year accumulation of files (numbering in the millions). The scan took ~60 hours, with the default 50% CPU usage limit, and my using the system for several hours during the scan. And it found only two potential problems in some KMD kits from years ago, and IIRC one of them was a Microsoft product. One irritation here is that during the scan MSE notifies you that it found one or more problems, but provides no details, and AFAICT the only way to get the details is to let the scan run to completion.
And on both systems, both running Windows XP SP3, minimizing the MSE window will sometimes leave an image of the window on the desktop. I’m not sure what this means, but I’m hoping it means that the developers are concentrating on the primary function of MSE, and ignoring cosmetic details.
