High CPU usage during scan

Comodo Internet Security - CIS Resolved/Outdated Issues - CIS
#1

During scanning my computer, CPU usage is very high. Usually goes between 15-60%, but sometimes it goes to 100%.

PC significantly slows down.

  1. CPU Athlon 64 X2 4600+
  2. Windows XP pro, service pack 3, 32 bit
  3. CIS 3.8.64263.468
  4. Antivirus - default settings
  5. Firewall - custom policy mode
  6. Defense+ - clean PC mode
  7. Administrator account
    2x1 GB ram Geil ddr2 800 paired
#2

During a context menu scanning CPU load goes around 80-90 %.