The software will not update because the official website doesn't exist anymore. If you try to visit its website, you will receive a Directory Listing Error. Alternatively, I recommend that you to visit the database of Software Informer to acquire an alternative because this one will not work anymore.
On the other hand, the software might have been blocked by your current antivirus solution. Try accessing the quarantine and check if the application is added there. Firewall is another cause for the lack of updates. Go to Start > Control panel > System and Security > Windows Firewall > Allow a program .. and add the application then perform a new update.