hello my friends

i am having problem with installing spyware doctor. i bought the cd  from best buy and tried to install it but couldnt register it so i checked their website.they provided me with lisence number and told me to uninstall my current version and download new version from their website . i tried to install it but it shows a problem during the installation . i skipped the problem and installed it anyway but it didnt let me register the license.the problem it shows is

Error

C:\Program Files\Spyware Doctor\avdb\av10-000.vdb

An error occured while trying to rename a file in the destination directory

computer experts please help me out.