I have a very old PC ( Acer2000) 32 Bits. On this machine I am running (Do not laugh) SCO Unix in an antique version : So Centos6 probes with the bootloader on this OS and other OS s.
There is a group that voluntarily maintains a 32-bit CentOS 7. I installed that on an old Dell Celeron desktop. The performance was so poor, it was unusable. Then, I tried the lubuntu distro, and that has been running smoothly since July. It is also well-maintained, as there are regular updates. Lubuntu is a derivitive of Ubuntu, which is a derivative of Debian. With Debian, the biggest difference is update (if you are using the command- line).
Todd Merriman Software Toolz, Inc.