Please be advised that Microsoft established the end of sales date for PCs preinstalled with Windows 7 Home Basic, Home Premium, and Ultimate on October 31, 2014. 

For more information on this matter this is the Microsoft site:   http://windows.microsoft.com/en-us/windows/lifecycle.

To ensure that Dell meets the Microsoft deadline of October 31, Configuration Services stop accepting Windows 7 Home Basic, Home Premium and Ultimate images after August 1 2014.