Windows 7 explorer.exe high CPU usage - tried everything I can think of

Are you using Task Manager to see what the CPU load is? You seem to say the load is divided between the 4 cores. What is the load on the hardest working?

Explorer.exe does not really have any services running in it, but it does have threads. Possibly one of those is causing the usage, but I cannot think of a Windows built-in utility that will show you the threads. There are some you could download from SysInternals called Process Explorer and Autoruns (Startup Items), it you so decide. There may be others, but I am not familiar.

If you have tried not starting everything you can in msconfig, the problem might be starting later or by something else.

There are things that do take some cpu cycles, at least for a time, related to the .Net install. If you are streaming any media, the load will be a little heavier. But since this seems to be a clean install, with no other software loaded, it does seem a little strange.

I've had similar experiences in the past with "invisible" sidebar gadgets running when I was developing some of my own. Luckily I always have a copy of Autoruns available. Helps you find those rogue runners you cannot see!

You saved my life, about two weeks ago I created a game trainer from cheat engine table, and after few days, my notebook started blowing like crazy. I did not know what was wrong, AV scan, spyware scan, a lot of tools: TuneUp 2012, System Mechanic 10, Auslogic 5, CCleaner, JvTools 16 2011, Registry Reviver, Slim Cleaner, Diskeeper 2011 and so on.
I was fighting for many days, but with no result.
Finaly I looked at process consumption and hohohoho at that, explorer.exe
Thank you very much for this post, icon on desktop without picture and cpu usage goes to around 40% on i3. Crazy, but true.
Thank you.