On most versions of Windows, you can use this installer to set up Tweego instead of installing it manually. If you cannot use said installer or prefer to set it up manually, carry on with these instructions.
Installing Tweego globally is probably your best bet. You can also install it locally, which has some benefits. I won't cover the latter right now, but it may be added in the future.
These instructions are for Windows 10. Windows 7 follows a similar process, but you'll need to add to the path variable manually. This guide may help you get started on other operating systems, too.
You can grab both Tweego and a collection of Twine 2 formats from Tweego's site. You may need to update some of the story formats in the collection. Regardless, download both and unzip them.
You can put Tweego anywhere, but the simplest places that are closest to your main drive's root are probably best. I usually put my stuff right on C.
I create a folder called tweego, then place the tweego binary and the story-formats folder inside it.
Just to be safe about it, make sure that the inside of the story-formats folder looks something like this.
Next we'll need to add Tweego to out PATH environment variable. You'll need to go to the System section of your control panel. You can search for it. In the picture below, it's the second option.
Go to advanced system settings.
Click environment variables on the bottom right.
Under system variables at the bottom, find Path. Highlight it and press edit.
On the resulting screen, click new on the top right.
Type in the path to the folder containing tweego. If you did this like I did, you'll type in C:\tweego\.
Click OK when you're done, but don't close the Environment Variables window yet!
This step is optional but recommended. You may as well do it while you're here to prevent potential headaches later.
Back in the Environment Variables window, click New.
Set the variable name to TWEEGO_PATH and the value to the path that leads to your story-formats folder. If you set it up the same way I did, that path will be C:\tweego\story-formats
Open a command prompt and type tweego. If the command is unrecognized, something was messed up, otherwise, an explanation of tweego should print out. Type in tweego --list-formats to make sure you've installed all the formats correctly and set up TWEEGO_PATH correctly. It should display all the formats you have in your story-formats directory.