Why are there multiples of svchost.exe running in my task manager running under system, local service, and network service, and am I allowed to close them? (A few years ago I closed explore.exe mistaking it for iexplore.exe and gave myself a scare ;-)) All but one take up about 3000-5000k, except for one which takes up 30,000k. I'm on a toshiba laptop, if it means anything.

It is a generic host process name for services that run from dynamic-link libraries. Do not end task it!

There is a great articale on svchost here that explains exactly what it is and several way to cut down the amount of them from running What is svchost.exe And Why Is It Running? :: the How-To Geek

If you see svchost is using 100% of your processor it is probably being caused by a known memory leak in that process follow the instructions at » How to Fix svchost.exe using 100% CPU / Memory Leak - Technibble - A Resource for Computer Repair Technicians & to get PC tech support help. to fix that specific issue.