I'm sorry about the issue. Do you mean you've upgraded to Windows 10, and now you want to get back to Windows 7?
If so, please click on the Start icon (which is the windows logo icon) located at the lower left corner, then click on Settings, then click on Update & recovery, then select the Recovery option on the left, then you will see the option to go back to your previous windows version there.
If it's something else, please let me know. Please reply at the box below to continue. Thank you.