Follow this tutorial A Clean install of Windows 7/Windows Reinstallation Guide which is located here: [URL] Locate your COA, likely under the battery of your system. Write down the 25 digit product key and the version of Windows 7 (it will likely be 64 bit Home Premium). See page 279-281 of the guide to download retail media or page 276 to request the Reinstalaltion DVD from Dell. Page 6-57 will guide you through the installation of Windows 7 including phone activation to Microsoft (not Dell). the phone activation isn't required if a Dell Reinstallation DVD is used. If you have any problems with the installation let me know. Otherwise if this answers your query could you please mark it as a verified answer. Thanks    
Hello, I recently upgrade to Windows 8 and had freeze when plugged in issue. I was able fix the issue after almost 2 weeks of googling (by changing the power setting to high performance).   Now I want to know how I could downgrade from W8 to W7. Points to note: I have googled so much without any luck. Can you help please? R    
Downgrade from W8 to W7