These are the steps to add Luvit (that is luvit, luvi, lit) to your system PATH on Windows. These instructions will be slightly different on old Windows, so in that case you could follow this general guide https://bit.ly/2QfZ8Ii.
GUI Instructions:
1. Moveluvit.exe, luvi.exe and lit.exe to a folder made specificlly for them, where you won't need to move them again, and remember where is that.
2. Copy the directory path you just created; you can do that by clicking at the directory path bar, then CTRL+C, or by right click then copy.
The copied path should be the parent directory of the executables, so for example if you have luvit at C:\Lua\Luvit\luvit.exe you will only copy C:\Lua\Luvit\ part.
3. Open the start menu (search menu), and search for System Environment, open it.
4. Click at Environment Variables..., located at the bottom right.
5. We are targeting the system PATH (user PATH would work as well), so put the mouse pointer over "System variables" fields and scroll down till you find a variable with the name of Path.
6. Click at the Path variable, then click at Edit, located bottom right.
7. Click New located at top right, a new empty field will show up, paste the directory you copied at step 2 there (By either CTRL+V or right click then paste).
8. Close any opened Command Prompt (or your terminal of choice) if any, then open a new one, and type luvit -v.
the version information should show up now. If that did not happen then you missed one of the previous steps so make sure you followed that carefully. Also make sure you opened a new CMD window and not an old one.