Even if your Windows is up-to-date it'll fail to install if the following KB's are not installed.
Here are the KB's required for iLok License Manager:
Make sure to download the appropriate installer (usually Windows 7 64-bit)
https://www.catalog.update.microsoft.com/search.aspx?q=kb3125574
https://www.microsoft.com/en-us/download/details.aspx?id=46148
Reference: http://avid.force.com/pkb/articles/en_US/Error_Message/iLok-License-Manager-error-Windows-7