Suddenly Windows seems to be using 43% of my system resources with the only application running being startup. This is worrying since I have I GB of Ram. I've scanned for viruses and trojans and my system is supposedly clean. What could be causing this? - Oh! As I type this I'm watching the Task manager and usage has just dropped to 5-10%. What could it have been? I logged on and logged off and the usage remained high. Could system restore have been the culprit. I don't have any tasks scheduled. also I notice that Windows Explorer is constantly using around 20,000 k and I have 4 instances of svchost.exe (2 system, 1 local service and 1 network service) - is this normal and would you expect one of the system svchost.exe's to be using around 15500 k?