Hello my name is ***** ***** I'll be happy to assist you. If you upgraded it to 10 you may have erased the factory image that was on the PC. You would normally access it by turning the PC on while tapping the F11 key What shows on the screen when you do this?
If you can't access it then it was probably deleted during the upgrade. You can download Windows 7 iso to make a bootable Windows 7 install disc from here: https://www.microsoft.com/en-us/software-download/windows7
You will need your product key which should be attached to the bottom of the PC or in the slot where the battery goes.