I looked at task manager for running processes, but to tell the truth I didn't understand much of what I was seeing.
Anyway, there was what I presume is a summary bar at the bottom, and this is what it showed:
Processes: 60
CPU Usage (varying) 0% - 10%
Commit charge: 370M/1490M
In the list of programmes the highest usage (if thats the right word) is 28000K
Physical memory available: 415316
You mentioned Ewido. I'm not keen on running another firewall programme - I've not got to grips with Trend Micro Housecall yet.
I hope this is of some help - excuse my ignorance.