Nothing you stated seems out of bounds. There can be reasons for the 100% CPU load as MSFT's Windows indexes files and stumbles on files it's decoder can decode or the old Spybot issue. But you'll have to tell a little more.
I have recently subscribed to MLB.com where I stream baseball games.
One system I use is a Pentium 4 desktop running at 3 Ghz with 1mg of Ram. It will generally run the games very well in full screen mode and high def. It will generally be registering a CPU usage of between 50-80%.
Second is a laptop running at 1.7 Mhz also with 1 mg of ram. It generally has a little trouble with FS mode but streams pretty well in HD with the regular sized screen. However, in HD it generally will register 90-100 on the Task Manager CPU Usage meter. Both computers seem to register fine as far as RAM.
I have not notice what I would consider excessive heat from either system.
My question and concern is whether there is anything inherently wrong with near 100% CPU usage for extended periods2-3 hours) or is this the normal operating profile for streaming depending on CPU speed of course. If so, what are the problems and repercussions of doing so.
Thanks for any input you may have.