Changed README.md

README.md

@@ -1,17 +1,15 @@
 # Screenbot
 
 This is a python bot which takes a screenshot of your main screen and sends it to a channel in slack
-
-Make sure the environment variable is a system variable (for windows)
-
+This was tested with python 3.7.3 on windows 10
 ## installing
 ```
 pip install -r requirements.txt
 ```
+Make sure the environment variable is a system variable (for windows) as variable `SLACK_BOT_TOKEN`.
+If you have difficulties setting environment variables, follow [this article](https://www.computerhope.com/issues/ch000549.htm)
 
-Usage:
+## Usage
 ```
 python screenbot.py 'slacktoken' 'channel'
-```
-
-This was tested with python 3.7.3 on windows 10
+```