Forget any Win 7 DVD or disc.
Go to someone else's computer, go to the Microsoft Windows 10 download site.
Download Windows 10 (microsoft.com)
(All of the instructions are on this site)
Find the option - install Windows 10 on another PC via the iso on a USB stick (A blank USB flash drive with at least 8GB of space) and create the installation media on the USB stick (which becomes "bootable").
Insert this in your PC and BOOT from it, You must also have connected the SSD or HD on which you want to install windows (preferably just formatted without windows on it) - you may need to press F8 or F12 to get the boot options menu (or something else - this is PC specific). If the installation drive has an old version of Windows - choose format at the install stage.
Boot from the USB stick and "install" Windows 10 as instructed. Put in the Key when requested (windows 7 or 10 key, either should work).
Windows 10 should install!