Compiling Erlang module using erl.exe - compilation

Question

I am extremely new to Erlang, I am trying to compile my first Erlang module and am getting an error that the no such file exists, although it does in fact exist.
Any suggestions as to why I erl.exe is failing to compile useless.erl is greatly appreciated.
Many thanks in advance!
erl.exe command prompt (note modules does in fact contain useless.erl)
1> filename:absname("C:/Users/modules").
"C:/Users/modules"
2> c(useless).
useless.erl:none: no such file or directory
(useless.erl)
-module(useless).
-export([add/2, hello/0, greet_and_add_two/1]).
add(A,B) ->
A + B.
%% Shows greetings.
%% io:format/1 is the standard function used to output text.
hello() ->
io:format("Hello, world!~n").
greet_and_add_two(X) ->
hello(),
add(X,2).

Answer 1

With that form, you need to execute erl the same directory as the module you are trying to compile. You can specify a file path when you use the c function. This will create a .beam file in your current directory:
Erlang R16B (erts-5.10.1) [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]
Eshell V5.10.1 (abort with ^G)
1> c("stackoverflow/passfun.erl").
{ok,passfun}
2> passfun:some_func().
hello