system idle at 99% is good, that how much of your cpu is available to use, it's not in use
Not when your total CPU usage is at 100%. Several processes use the system idle process. Get TCPview from support.microsoft.com/systernals and you will be able to see what is using this.
I was getting high CPU usage and Process explorer was showing that “system idle processes” was taking up 98% of the cpu time.
I used TCPview & you can see what processes are using that process and end them. They were mostly just web ads and network domain connections that just came back after ending. One thing that uses system idle processes is windows updates, so if you can, turn off automatic updates. You may also want to turn of automatic system restore, and delete files in the Temp, downloaded files, downloded programs folders and any such temporary folders.
So, I did a google search and did 3 things. Now I have a bunch of stuff loaded on my laptop and cpu usage is at 0%. The problem still comes back once in awhile, when using Office 2007, so I am looking into that, but my overall cpu usage is much lower now.
This is what I did:
1) The right click visual effect can kick off the high cpu usage. Follow the steps in this picture:
2) Saved the following to a batch file and ran it (this will re-register files that are used by automatic updates):
Net stop wuauserv
Net stop bits
Net stop cryptsvc
regsvr32 %windir%\system32\atl.dll /s
regsvr32 %windir%\system32\jscript.dll /s
regsvr32 %windir%\system32\msxml3.dll /s
regsvr32 %windir%\system32\softpub.dll /s
regsvr32 %windir%\system32\wuapi.dll /s
regsvr32 %windir%\system32\wuaueng.dll /s
regsvr32 %windir%\system32\wuaueng1.dll /s
regsvr32 %windir%\system32\wucltui.dll /s
regsvr32 %windir%\system32\wups.dll /s
regsvr32 %windir%\system32\wuweb.dll /s
regsvr32 %windir%\system32\wuauserv.dll /s
regsvr32 %windir%\system32\wupdmgr.exe /s
regsvr32 %windir%\system32\wups2.dll /s