On Thursday, February 23, 2012 05:35:32 PM Wuxi Ixuw wrote: > Ok, I've found many versions from it, one for 700 MB and others for a > DVD, which one I should get? While I specifically stated the installation media, you should get both the DVD1 and DVD2; specifically, assuming a 32-bit system (you mentioned trying on a Pentium 4 or Pentium D, so 64-bit may not be an option, and isn't really necessary for a 'lab' machine anyway; you do need as much memory as you can cram in that old Optiplex, with an absolute minimu of 1GB (and it's going to top out less than 4GB anyway....)), you need to download, from a mirror: CentOS-6.2-i386-bin-DVD1.iso CentOS-6.2-i386-bin-DVD2.iso While DVD2 is somewhat optional, it won't hurt to have it on hand just in case. The LiveDVD and LiveCD options boot up to a usable desktop, and you can install from them, but if you're wanting the *server* install experience you need the others, not the LiveDVD or LiveCD. Now, go give it a whirl, make sure you read the documentation on installation on the CentOS.org website, and come back in a few days when you've played with that installation a while.