Unable to install Windows 10 x64

[WyrdNyrd]

Upgrading from Windows 7 x64, I performed the free update to Windows 10 and verified it was activated.
I wanted to perform a clean install of Windows 10 after that. I download and created the Windows 10 x64 ISO on a USB drive using the Microsoft tool. I only selected the x64 option.
After performing the clean install I check the system properties and it's showing Windows 10 32-bit.
I have recreated the USB ISO again and it's still only installing the 32-bit OS.
What am I doing wrong?

 

[Trouble]

Have you checked the ISO itself.
If you mount it, (right click and choose mount) does the name reflect 64 bits
CCSA_X64FRE_EN-US_DV5 (or something similar)
OR
CCSA_X86FRE_EN-US_DV5
Check the sources folder. That should be a dead giveaway.
The size of the install.wim file for a 64 bit version should be somewhere in the neighborhood of 3,486,381KB
WHILE
The size of the install.wim file for a 32 bit version is considerably smaller, somewhere in the neighborhood of 2,579,698KB