NAV will not install

Hi,

I have a computer that had the BugBear virus. Unfortunately, the user did not have anti-virus software loaded. I have used the BugBear removal tool from teh Symantec site which told me that there were two files infected and that it had successfully removed them. I then went on to install Norton’s Internet Security 2000. It would get to a particular part in the install and then just disappear. I have tried many times now to install the program to no avail.
Can anyone please tell me why I cannot load the software on? It is frustrating because I want to do a complete scan of the pc to check for viruses.

Look forward to a response.

Mil