Wonky title but I'm awful at naming threads 
I have Windows 7 ultimate that was upgraded to I think Windows 10 PRO and I'm due for a format, it's something I've always done was semi regular formats to keep my PC running the best it can as I have nothing on my gaming computer I need to worry about keeping.
Anyway, does anyone know how that would work? How would I format my PC without a physical copy of Win10? Do I just format, install Windows 7 and then upgrade to 10 again? Or do I like format and use a memory stick to install 10 like before, assuming that the free upgrade files are still around.
Cheers!

I have Windows 7 ultimate that was upgraded to I think Windows 10 PRO and I'm due for a format, it's something I've always done was semi regular formats to keep my PC running the best it can as I have nothing on my gaming computer I need to worry about keeping.
Anyway, does anyone know how that would work? How would I format my PC without a physical copy of Win10? Do I just format, install Windows 7 and then upgrade to 10 again? Or do I like format and use a memory stick to install 10 like before, assuming that the free upgrade files are still around.
Cheers!