Hi Mark, This is most likely because you don't have your current directory in your PATH variable. When you execute something your shell searches through the directories listed in your PATH variable (try "echo $PATH" to see its contents). In short run "./a.out" to execute a.out from the current working directory and read about your PATH in "man bash" (bash is usually the default shell for linux, however there are others). Cheers, Craig. On Wed, 2005-10-05 at 22:12 -0400, Mark Peskir wrote: > I have made some very small c programs. They compiled with no errors under > gcc, and produced an a.out. However, when I type a.out to run, I get "a.out: > command not found". > > I am running the latest gcc (4.0.2) on an x86 machine using Mandrake Linux > 10.1 (not Mandriva). Thank you for helping this Linux beginner!