Maxime Trepanier :
Can I just install the creational tool of win 10 64 bit on a usb and then open it and double click on setup.exe for a clean install of win 10 from 32 bit to 64bit? Thanks
No. The creation tool will download an image file from Microsoft.
You then need to use something (like PowerISO) to extract that image file and burn it to a DVD or create a bootable USB drive. At that point, you'd reboot the computer and tell it to boot from the DVD/USB drive (usually a BIOS flag), upon which it will format the hard disk and install Windows 10.
Back up your stuff - you will lose everything on the C drive in this process.