You could do as I did.
Disable your current anti-virus and firewall. Enable Windows firewall. Download AVG FREE and run it.
If the game works, great. If not, then uninstall it and reload it.
I did a fair bit of reading about AVG and it came highly recommended.
It didn't just allow this game to run, but others (Mystery Case Files etc) that I had similar problems with, some just wouldn't run at all.
My whole system now runs a lot faster, especially loading web pages.
Virgin PC Guard has now been completely removed from my system.