[Docs] Add warning about PATH on Windows (#2791)

docs/install_windows.rst

@@ -37,22 +37,25 @@ Manually installing dependencies
 * `Python <https://www.python.org/downloads/>`_ - Red needs Python 3.7.0 or greater
 
 .. note:: Please make sure that the box to add Python to PATH is CHECKED, otherwise
-          you may run into issues when trying to run Red
+          you may run into issues when trying to run Red.
 
 * `Git <https://git-scm.com/download/win>`_
 
-.. attention:: Please choose the option to "Run Git from the Windows Command Prompt" in Git's setup
+.. attention:: Please choose the option to "Run Git from the Windows Command Prompt" in Git's setup.
 
 * `Java <https://java.com/en/download/manual.jsp>`_ - needed for Audio
 
-.. attention:: Please choose the "Windows Online" installer
+.. attention:: Please choose the "Windows Online" installer.
 
 .. _installing-red-windows:
 
 --------------
 Installing Red
 --------------
 
+.. attention:: You may need to restart your computer after installing dependencies
+               for the PATH changes to take effect.
+
 1. Open a command prompt (open Start, search for "command prompt", then click it)
 2. Create and activate a virtual environment (strongly recommended), see the section `using-venv`
 3. Run **one** of the following commands, depending on what extras you want installed