docs,Windows,install: add info about envvars
Document the envvars that Bazel (still) requires,
how to set them, and to what value.
RELNOTES: none
@@ -17,11 +17,33 @@ title: Installing Bazel on Windows
### Getting Bazel
-[Download Bazel for Windows from GitHub](https://github.com/bazelbuild/bazel/releases).
-Look for `bazel-<version>-windows-x86_64.exe`, e.g. `bazel-0.15.2-windows-x86_64.exe`.
+1. [Download Bazel for Windows from GitHub](https://github.com/bazelbuild/bazel/releases).
+
+ Look for `bazel-<version>-windows-x86_64.exe`, for example
+ `bazel-0.16.1-windows-x86_64.exe`.
**Tip:** Rename the binary to `bazel.exe` and move it to a directory on your
-`%PATH%`, so you can run Bazel by typing `bazel` in any directory.
+ `%PATH%` (for example to `c:\bazel`), so you can run Bazel by typing `bazel`
+ in any directory.
+
+1. Edit environment variables.
+
+ Open the "Environment Variables" dialog box from Control Panel or Start
+ Menu, and add or edit the following variables under the "User variables"
+ section:
+ 1. **Edit `Path`**. Add new entries to the beginning of the list:
+ * The directory of `bazel.exe`. (Example: `c:\bazel`).
+ * The `usr\bin` directory of MSYS2. (Example: `c:\msys64\usr\bin`).
+ * If you will build **Python** code: the directory of `python.exe`.
+ (Example: `c:\python3`).
+ 1. **Add `BAZEL_SH`**. Its value must be the path to MSYS2 Bash.
+ Example: `c:\msys64\usr\bin\bash.exe`
+ 1. **Add `JAVA_HOME`** (if you will build **Java** code). Its value must be
+ the directory where you installed the Java JDK 8, for example
+ `C:\Program Files\Java\jdk1.8.0_152`
+
+ **None of these paths should contain spaces or non-ASCII characters.**
+
### Other ways to get Bazel
