Lately, people seem to be experiencing an issue where Shogun 2 is launched, reaches the splash/legal information screen, and then stops altogether, ending with a crash. (Please note that if you are starting Shogun 2 for the first time, that is an unrelated non-issue, as the game has to compile shaders, which can take a while, up to 10 minutes.)
To combat this issue, there is a two-step method to follow:
1) First, check your web browsers (Internet Explorer, Firefox and Google Chrome) for addons/plugins/extensions. Disable or uninstall these one by one and see if the issue is fixed. Especially take note of anything referring to Incredibar, a toolbar for Internet Explorer and Firefox which is actually malware. Check for any other forms of malware similar to that and remove as needed. Ensure that your anti-virus software is up to date.