First of all Kaspersky 2010 is hanging up computers. The symptoms happen when you upgrade from Kaspersky Internet Security 2009 to Kaspersky Internet Security 2010. The next time you start the computer it takes several minutes before you can click on something and anything will happen. The solution is to uninstall Kaspersky and then reinstall Kaspersky Internet Security 2010. That has worked on every computer that has had the problem so far.
Here is an interesting thought, all the computers that have had the problem were 'old installations' that most likely have had a 'fixed' virus on them. In fact one of the installations had Windows (Virus) Vista on it, but had since been upgraded to WIndows XP. So long term the better solution would be Format C: and start over as there may be some sort of a virus/corruption that is causing the problem.
The second thing that has come to my attention is a new method in the virus attacks. When you visit an infected web site they may try over 1,000 ways to infect your computer. So though matter how hard you try to keep your computer up to date it is a hopeless case. But now they have a new attack vector, they are trying the same thing in emails! They send a spam that attacks your anti-virus as well as attacks Microsoft Outlook looking for any of several hundred vulnerabilities. This results in Outlook Restarting untill you unplug your network cable. The solution is to use web mail and delete the garbage. Also update to at least Outlook 2003 with all of the patches and updates installed as well.