viktornegovan :
I'm currently using Windows 10 and I want to install Win7 because I cannot stand all the issues I'm having with 10. I have the disk and all I want to know is if I will lose all my data on my drives if I install Win7
If you upgraded to Windows 10 from Windows 7 and it has been less than 30 days, then you can downgrade and go to previous operating system... 'Go back to Windows 7'.
If it has been 30 days or more you will need to perform a clean installation of Windows 7 and you should definitely backup your files since all data will be wiped.
Either way I would backup the files since you never know what can happen.
Better safe than sorry.