Trouble Reinstalling Norton Family Safety

Hi, All,

I have successfully installed and used Norton Family Safety on two laptops running Windows 7, one desktop running Windows 7, and one laptop running Windows XP.  I have been trying the free version for the past month before considering upgrade.  

Recently, I noticed NFS inexplicably stopped working on the desktop.  After stopping my antivirus, windows defender, and firewall, I tried to reinstall it, but I received a generic, non-specific error message asking if I would like to retry; it wouldn't allow it.  I downloaded the more recent version, and when I try to install it, it just hangs.  

I have tried uninstalling, but the program is not showing up on the computer, even when using a third-party uninstall tool.  I tried searching for all Norton folders and deleting, but I still can't reinstall it.  

Online chat agent did remote support.  All they did was try installing it in safe mode; no luck.  They also suggested I hardwire my internet instead of using WiFi; no luck. 

I really like this program.  What can I do to get this back on my machine?  It's a brand new desktop.  Could some other program be interfering with it?  Is there a way to clean uninstall it?

Thanks for any and all help.