After leaving the PC idle for a few hours, the CPU usage increases to 20%. This is a very large increase from the CPU usage after starting up (and a few hour later while using the PC) were the usage is approximately 3%.
CPU: Core I7 920 (2.8 quad core)
Mother board: MSI X58 Platinum
Win 7: 64 bit, clean install
System and system interupts are the biggest chunks (~9% and ~5% respectively)
Downloads: Firefox, MSN messenger, yahoo messenger, Avira antivirus, Ad-aware , Winrar 64 bit (drop was occurring before avira, adaware and winrar downloads)
Scan with avira and ad-adaware come out clean
despite the high CPU usage, computer still runs smooth, have not attempted with any games though.