Update WINDOWS_SERVICE.md (#1669)

1. Added further clarification on running commands in PowerShell.
2. Added double quotes to file paths.

docs/WINDOWS_SERVICE.md

@@ -6,19 +6,18 @@ the general steps to set it up.
 1. Obtain the telegraf windows distribution
 2. Create the directory `C:\Program Files\Telegraf` (if you install in a different
    location simply specify the `-config` parameter with the desired location)
-3. Place the telegraf.exe and the config file into `C:\Program Files\Telegraf`
-4. To install the service into the Windows Service Manager, run (as an
-   administrator):
+3. Place the telegraf.exe and the telegraf.conf config file into `C:\Program Files\Telegraf`
+4. To install the service into the Windows Service Manager, run the following in PowerShell as an administrator (If necessary, you can wrap any spaces in the file paths in double quotes ""):
 
    ```
-   > C:\Program Files\Telegraf\telegraf.exe --service install
+   > C:\"Program Files"\Telegraf\telegraf.exe --service install
    ```
 
 5. Edit the configuration file to meet your needs
 6. To check that it works, run:
 
    ```
-   > C:\Program Files\Telegraf\telegraf.exe --config C:\Program Files\Telegraf\telegraf.conf --test
+   > C:\"Program Files"\Telegraf\telegraf.exe --config C:\"Program Files"\Telegraf\telegraf.conf --test
    ```
 
 7. To start collecting data, run: