There are a lot of PC users out there running 64-bit Windows instead of 32-bit, but who either don't realize it or just haven't bothered installing the 64-bit versions of their favorite programs. At least one major program will soon make the switch automatically for users.
Beginning with Chrome 58.0.3029.96, which was released on Tuesday, Google will automatically migrate select users to 64-bit Chrome from the 32-bit version.
There are a few requirements for the switch to happen. First, you have to be running 64-bit Windows and have 32-bit Chrome installed. Your system also needs 4GB or more of RAM. Google says auto-update also has to be enabled, but that should be the case for the vast majority of home users.