Before trying to use the Small Basic EV3 extension you should make sure you are familiar with basic programming concepts such as 'variables', 'For loops', 'While loops' and 'arrays'. If you don't yet have such knowledge then a great way to start would be to work through the Small Basic tutorial HERE (PDF file).
Some of the text below comes from this page which gives a good introduction to Small Basic and the Small Basic EV3 extension.
Once you have installed Small Basic on your Windows computer you will need to also install the Small Basic EV3 extension suite in order to be able to program the EV3 using EV3 Basic. The term 'EV3 Basic' refers to Microsoft Small Basic with the EV3 extension. EV3 Basic is an easy-to-use development environment where you can build and run programs that control the EV3 Robots.
Note that although the EV3 extension has now been updated more than twenty times and is quite stable, there is always the possibility (as with any software) that there may be some bugs. The software is provided 'as is' and you use it at your own risk. Neither the developer of the extension nor the author of this site can accept any responsibility for any damage caused to your computer or EV3 brick.
Download the installer file EV3BasicInstaller.msi from the current release at github.com/c0pperdragon/EV3Basic/releases. When you run the installer you may get a security message from Windows - you will have to give permission for the file to be installed in order to continue (in Windows 8 or 10, click 'more info' then 'install anyway').
You should also download from GitHub the Small Basic manual and the example files.
If you are updating the EV3 Basic extension then you should use the Control Panel to uninstall the old version of the extension before installing the newer version. Be sure to uninstall only the extension and not Small Basic itself!
A tip from user Mr. S. T. Prasad: If you have a problem getting the EV3 extension to work with Windows 10 then open Control Panel >> Programs >> Programs and Features >> Turn Windows Features on or off and make sure that the checkbox for .NET Framework 3.5 is turned on.
Make sure the standard Lego EV3 software is not running (see the note at the bottom of this page). Start ‘Microsoft Small Basic‘. Type 'm' (without the quotes) in the blank program area. If all is well you should see a reference to 'Motor' in the 'Intellisense' box that appears. This means that Small Basic has recognised the presence of the extension. If not, try reinstalling the extension.
You can use the Intellisense documentation to learn about the various parts of the EV3 extension.
You are now ready to start exploring the power of Small Basic. If you are a novice to programming, use the link “Beginning Small Basic” on the Small Basic homepage to learn about fundamental concepts and how to generally create programs.
When an EV3 is connected (by USB cable or Bluetooth or Wifi) you can run your EV3 Basic programs instantly on the EV3 by clicking the Run button or pressing the F5 key. We call this 'working in PC mode'. Note that pressing the Run button or the F5 key does NOT download the program into the EV3's memory. Alternatively, you can use EV3 Explorer to compile the EV3 Basic program into a form that the EV3 can understand and download it into the brick's memory so that it runs there instead of on the PC. This way of working is called 'brick mode' and it is the recommended way of working with wireless connections except if your program makes use of functions that require Small Basic features such as the Small Basic graphic window.
Important note: EV3 Explorer and the Lego EV3 software (EV3-G) each demand exclusive control over the brick, therefore you must close the Lego EV3 software before attempting to use EV3 Basic (Small Basic with the EV3 extension) or EV3 Explorer. You can run Small Basic and EV3 Explorer at the same time in which case EV3 Explorer will have the connection to the brick and it will not be possible to run EV3 Basic programs directly from Small Basic. Running Small Basic and EV3 Explorer at the same time is nevertheless very useful when you have a wireless (WiFi or Bluetooth) connection to the brick and want to run your programs in brick mode rather than PC mode (brick mode is more reliable than PC mode when using wireless connections). You can simply save your program in Small Basic and (compile and) run it in EV3 Explorer with just a couple of clicks and without closing either program.
OK, now the fun starts! Click this link to start learning EV3 Basic Programming...