Since KAV 4 was released many people, including myself, have reported that it is a resource hog with 'typical' installation selected. This problem was seen even with very high spec machines. With accepting this default installation (with the Control Centre installed) and the default Monitor Settings I found that KAV used up about 54mB of memory and slowed down my computer considerably ( Pentium 4, 512mB memory). Despite e-mailing Kaspersky both in Russia and the UK I received no replies so I relegated KAV to a backup scanner. However, support at the Kaspersky UK site eventually contacted me( my previous e-mails had gone to an old address) this week and over several e-mails with suggestions I have now found that the Monitor has virtually no impact on my CPU. I have found the following steps to be crucial for the KAV Monitor being able to run in the background without little effect on system resources; 1. Do not accept the 'typical installation' - accept 'custom' installation and deselect 'Control Centre' from the options given. 2. Once you have installed KAV and rebooted, right click on the monitor in the system tray and choose 'Monitor settings'. 3. In 'Scan files of the following types' - choose 'all infectable' 4. In 'Scan compound files' I have none of the boxes selected. Some of these compound files if selected will slow down your computer considerably and the program brings up a box warning you of this if these options are chosen. However, I have selected everything in the KAV Scanner options. With the above settings KAV now only takes up between 11-20mB memory with the Monitor running and there is no impact on the speed of my computer( I have also tried these settings on a Pentium 3 with only 256mB memory and again there was very little impact on the speed of this computer). My experiences with KAV emphasise the importance of good support with any (AV) software and the importance of not always accepting the default settings offered to you. I have now 'promoted' KAV 4 to my main scanner and within one hour it found and deleted a trojan trying to enter my system.