IRB help

I’m new to Ruby. I installed Rails on Windows 8.

When I type mkdir in IRB, I’m getting this. I tried running the IRB as administrator too, and still get the same result

irb(main):001:0> mkdir lesson2
NameError: undefined local variable or method lesson2' for main:Object from (irb):1 from C:/RailsInstaller/Ruby1.9.3/bin/irb:12:in
irb(main):002:0> cd lesson

I'm new to Ruby. I installed Rails on Windows 8.

When I type mkdir in IRB, I'm getting this. I tried running the IRB as
administrator too, and still get the same result

irb(main):001:0> mkdir lesson2
NameError: undefined local variable or method `lesson2' for main:Object
        from (irb):1
        from C:/RailsInstaller/Ruby1.9.3/bin/irb:12:in `<main>'
irb(main):002:0> cd lesson

Those commands (mkdir and cd) are not supposed to be run in irb (which
is for ruby code), but in a console window. Whether they work in
Windows anyway I do not know. I strongly advise not to use Windows
for developing RoR applications, it is much easier in Linux (Ubuntu
for example) or Mac.

Colin

I used the cmd prompt Windows and type IRB to start and get that error.

IRB is not the command line. Use the command line to mkdir.

I got it working. Thanks for helping.