Do you mean unblock as in Firewall permissions or stop VirusScan from deleting it as malware?
if the former, then open SecurityCenter
Click Web and Email Protection
Click Internet Connections for Programs
Click the word Programs at the top of that section to arrange them alphabetically
Locate the program or servuce that runs it and make sure it has full permission, use the Edit button if necessary.
If the latter then there we would need to know the name of the software/game and what it is detected as.
Meanwhile all you can do is outlined here: https://community.mcafee.com/thread/2016