I am using selenium with python and have downloaded the chromedriver for my windows computer from this site: http://chromedriver.storage.googleapis.com/index.html?path=2.15/
You can test if it actually is in the PATH, if you open a cmd and type in chromedriver
(assuming your chromedriver executable is still named like this) and hit Enter. If Starting ChromeDriver 2.15.322448
is appearing, the PATH is set appropriately and there is something else going wrong.
Alternatively you can use a direct path to the chromedriver like this:
driver = webdriver.Chrome('/path/to/chromedriver')
So in your specific case:
driver = webdriver.Chrome("C:/Users/michael/Downloads/chromedriver_win32/chromedriver.exe")