System Idle 100% make pc slow

Hi all,
Today I opened task manager & found system Idle worked 97-99% & pc began to run slow

I think this slow process occurred for system Idle because other process (above 105) are working below 10%
My notebook has core i7 2.3 Ghz (3 gen), 8 GB ram & 2 GB gtx 660m. I think that specification is enough to run windows 7
More over, my desktop pc works fine with the process of sytem idle 50-56%. The interesting thing is that pc has Pentium 4 with 2 Gb ram
I want to know: How can I fix system Idle process 95% above..
Tnx

from here:
System Idle Process - Wikipedia, the free encyclopedia

Because of the idle process's function, its CPU time measurement (visible through Windows Task Manager) may make it appear to users that the idle process is monopolizing the CPU. However, the idle process does not use up computer resources (even when stated to be running at a high percent), but is actually a simple measure of how much CPU time is free to be utilized. If no ordinary thread is able to run on a free CPU, only then does the scheduler select that CPU's System Idle Process thread for execution. The idle process, in other words, is merely acting as a sort of placeholder during "free time". Because of the idle process's function, its CPU time measurement (visible through Windows Task Manager) may make it appear to users that the idle process is monopolizing the CPU. However, the idle process does not use up computer resources (even when stated to be running at a high percent), but is actually a simple measure of how much CPU time is free to be utilized. If no ordinary thread is able to run on a free CPU, only then does the scheduler select that CPU's System Idle Process thread for execution. The idle process, in other words, is merely acting as a sort of placeholder during "free time".