I was looking at How to install 64-bit Tor Browser on Windows 10 and seeing that I went to https://www.torproject.org/projects/torbrowser.html.en and downloaded the alpha build which was released with 64-bit richness there. I upgraded intoto to the current build which sits in C:\$Username\Desktop/$releaseversion-release.
I then went into C:\Users\generation2\Desktop\Tor Browser\Browser\defaults\pref\channel-prefs after closing down the browser where I changed from alpha to beta channel.
It should get invoked the next time a new version comes in if I'm not wrong. Looking forward to know if I missed anything.