so you did download the .run
that is an executable file
You do not "open" it
so what exactly did you do with the .run ?
you normally run the ".run" program
it is a type of installer
so the 32 bit ?
i take it that this is a old computer that is using a 32 bit hardware
you dl it
open a terminal
cd / to/the/location/you/saved/the/file
chmod +x metasploit-latest-linux-installer.run
Fallow the instructions in the "Linux_InstallationGuide.pdf"
the full install instructions are in the pdf -- i am looking at it as i type
cent like RHEL dose not use"sudo" by default
use "su" or " su -"
or set up sudo ( disabled by default)