Your virus scanning software might be trying to quarantine some of game's files.
In McAfee they might be labeled as an "Artemis" trojan, however there is no virus. This is McAfee's way of labeling unknown files that could potentially be harmful (which ours are not).
To fix this issue, un-quarantine any game files your anti-virus software has quarantined. In some rare cases, you might need to run the installer again with your anti-virus software turned off.
