I just recently unstalled kaspersky antivirus 6.0 for avast but i noticed that my Security Center was not screaming at me because I have no Anti-Virus installed. Now my Security Center still shows Kaspersky installed and up to date. There is nothing in the registry or in Program Files .
In kaspersky forum they reccomand this
1. Temporarily disable the WMI service (Windows management instrumentation) in: Start >Run > type: services.msc and in there find/stop WMI
2. Next delete the C:\windows\system32\wbem\repository folder
3. Restart the WMI service & restart the computer