I have 64-bit Windows 8.1 Pro, Lenovo X220. All updates are installed (both Windows and from Lenovo Solution Center).
Every time my computer starts, one of the processes uses 25% of CPU (until computer is restarted). Task manager says it is "NT Kernel & System".
I did not find anything useful when googling (except "update windows, update drivers"). For a while I thought I can use kernview and Process Explorer - unfortunately, Kernrate Viewer is not available for Windows 8 as far as I can see.
Windows installation is quite new, antivirus updated (Syamantec), no malware detected (AdwCleaner, MalwareBytes)
How do I find what is starting this process and why it has such high CPU usage?