Pentoo comes in many flavors and it is important to choose wisely. Right now, you have two main choices: Choice 1: Full or not (you do not want Core) If you plan to install, get the Full iso. If you want all the tools, get the Full iso. If you want to update anything and need the build time tools to do that, get the Full iso. Basically get the Full iso unless you are only planning to run live and don't need any of the more rare tools. If you are reading this, you don't want the core iso. No one wants the core iso, it has no X, no security tools, and it basically only useful for kernel testing. Choice 2: amd64 or x86 Reality is, no one tests things on x86 32 bit (i686) anymore. I don't just mean us, I mean software devs, distro devs, and even kernel devs. No one cares about old hardware. If you download the x86 builds, it will run on anything Pentium M or higher, but reality is that the amd64 (x86_64) builds are not only faster, but hugely better tested. Pick amd64 (x86_64) unless you have a really good reason (like wanting to support ancient 32 bit x86 hardware).