Solidifying the executable software set of a computer

System and method for solidifying (or "freezing") the set of software and configuration data available for execution on a computer. Any additional software installed on the computer after the solidification process will not execute, regardless of whether the installation is initiated or otherwise performed by a person with administrative privilege. The ability to allow new or modified software to execute on the computer rests with an integrity server separate from and outside of the solidified computer. The solidification of software and configuration data proceeds on a level of granularity selectable by the integrity server and any operators thereof.