The recent virus attacks that took place in Iran by a virus called Stuxnet which can enter crucial installations like nuclear plants and other installations has posed a great threat to countries and systems all across the world. It takes advantage from a security hole in the Windows operating System. Stuxnet is capability to reprogram the programmable logic controllers (PLCs) and hide the changes.This poses a grave threat to government and military installations. So it has become very important to create a secure operating system environment for such kind of installations.