follow the below method ti download repo
https://help.ubuntu.com/community/Repositories/Ubuntu
just install it....and all the commands are entered in ubuntu
did you install it like this method
(WINDOWS OPTION 2) If you want Linux instead of Cygwin, and you want it to be installed safely (no partitions or bootup modifications), then you'll need to download a "virtual machine" in Windows.
Using virtual machine software means you don't need to go through the trouble of creating a brand new partition or wiping out your hard drive just to install Linux. You can run it inside of Windows.
NOTE: You'll need a fast PC with lots of RAM!