I can't run executive file

I write hello program: hello.F90

write (*, *) ‘hello’
end

And generate executive file: hello

pgf90 -o hello hello.F90

Then run hello

hello

the system gave me error: Command not found

What happened here? Thanks

BTW, I already bought the lincense.

Did the exe get created? Do an ‘ls’ and see if “hello” is there. If its is there, then you need to add “.” to your PATH environment variable or run using “./hello”.

-Mat