Nimda vs McAfee

Upon trying to run Vscan, I found it to have become corrupt or affected by the virus. I uninstalled the software, deleted any related files on the drive and then attempted to reinstall it. It blew up with an error message that install had been interrupted and try again. Someone told me to delete any registry entries, so I did a find in the registry for ‘Network Associates’ (the program folder) and deleted what was found. Tried to reinstall again and it still blew up. Any suggestions?