System Idle is well discussed so when it goes to 99% or 100 your machine is doing nothing or waiting for some I/O to complete.
RAM should by design go to as close to 100% since unused RAM is wasted RAM.
I think you need to tell more what is going on but as presented, that's not it. If I were to guess you have a slow PC after installing Windows 7. This is true for most PCs today. Until we finish the install with drivers and maybe an app, the machine is not doing its best.
CPU and RAM overload. And only because of System Idle and svchost.exe SYSTEM. They are taking 50/50. Just to make sure that there are no viruses I reinstalled windows (7) totally formated hard drive and even befor installing Google Chrome, CPU was 60% and RAM 3.4 GB (I have 6 GBs). In BIOS jumpefree configuration everything is on auto, now, but before i try to configure RAM overclocking and after some "configuring" I had to remove CMOS battery for a while because that keyboard stuck. Then everything went ok but after an hour all this began to happen. Motherboard is asus P5K SE with AMI BIOS, CPU e6550. Any idea,please. I'll be very much appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic