I had a similar problem when testing the new CIS 6.1 when I wanted to installed Avast free back, follow the instruction from DavidR first and don’t install avast just yet leave number 4 alone until you’ve checked all the kaspersky sub directories are gone (deleted) make sure nothing is left over check sub directories in ‘Program Files’, 'Program Files (x86), ‘ProgramData’, ‘Users\your name\AppData\Local’ and ‘Users\your name\AppData\Roaming’. Reboot you’re computer and run CCleaner to clean out you’re registry for leftovers reboot again and THAN install Avast Internet Security.