1. You can do that check the Box.
2. You could reinstall the correct way ( so you don't have to check the WITHOUT_GIT box all the time). I do have a general tutorial on how to do that https://www.youtube.com/watch?v=_pOZUqGanSo. (Just pointing that out)
3. It is just a path issue, so just add it to your variable path:
1. Right click on Computer.
2. Click Advanced System Settings
3. Click Environment Variables inside the Advanced Menu
4. Under System Variables, scroll to PATH
5. Add ;"C:\path\to\git\bin";"C:\path\to\git\cmd"