Use the 64bit if that is what your PC is. The other thing he is talking about is the Boot Menu that Macrium can install for you. It will show up when you boot the computer. I have mine set to 5 seconds. I boot my pc and it comes to a screen that shows Windows 10 highlighted and Macrium Recovery under it. It shows for 5 seconds then will load Windows 10 if I do not touch it. It is great to have if Windows boot gets messed up somehow.

You can do this by opening Macrium. On the "Other Tasks" menu at the top. Click there, then click on Add Recovery Boot Menu Option. Then click OK on the message that pops up.

Backup and Restore with Macrium Reflect Windows 10 Tutorials

Scroll to PART TWO, step #7. It has pictures to show you.