The Installer automatically installs the 32Bit Version on my 64Bit Windows10 PC. How can I install the 64Bit Version?
Tor is only distributed as a 32 bit application.
Tor Browser is currently only distributed as a 32bit program for Windows. This is quite common for Windows applications, which natively supports 32bit applications on its 64bit operating system.
It's not currently available but it's likely that they will eventually be introduced.