An average Windows 7 PC uses around 100-150MB for Paged Kernel Memory ( PKM) and around 50 MB of Non Paged Kernel Memory (NPKM). If you look in task manager ( Ctrl+Alt+Esc ) , You can see the memory usage under the ‘Performance’ Tab.
If at all you are to be worried, It should be when the Kernel Memory goes way beyond logical levels. The Cached Levels will be usually high due to the Readyboost feature in windows , and they are freed when necessary. But not the NPKM and PKM.
Case 1: High Usage of NPKM – Non Paged Kernel Memory.
Issue#1 : WFP memory leak
One of the main causes of an NPKM Leak is due to the Windows Filtering Platform (WFP) causes memory leak.
Fix for that is available at : Microsoft Support KB979223 .
Applications which causes memory leak due to this issue includes ESET Nod32 Antivirus causing NPKM when large amount of data is downloaded over a small time period , say 10 GB over 1 day.
Case 2: High Usage of PKM –Paged Kernel Memory.
Issue#1: Memory leak when large amount of shared files are accessed.
When shared files which are hosted on a file server, Windows allocates certain space using Ksecdd.sys driver, But by default, doesn’t free up the space. This issue is less common than the above one, but it has occurred to me in the past.
Fix for that is available at : Microsoft Support KB2612966 .