Analysis shows that there are about five faults per 1000 lines of code in carefully made programs, which means that one million lines of codes will have 5000 faults. Windows XP has approximately 45 million lines of code. How many faults does Windows XP have? A simple calculation shows that there are 45 x 5000 = 225,000 faults in Windows XP. Discuss the following questions: (1) Isn't it a miracle that the system operated at all with this number of faults? (2) Why not remove the faults?