Where Chrome Driver expects Chrome Browser installed? It depends on your OS as documented at https://github.com/SeleniumHQ/selenium/wiki/ChromeDriver
This page show you a table:
|OS||Expected Location of Chrome|
|Mac||/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome|
|Windows XP||%HOMEPATH%\Local Settings\Application Data\Google\Chrome\Application\chrome.exe|
How about the case of Windows7, Windows10? It seems that the document was written years ago when XP and Vista were main players, and it has not been updated since then, so that it does not mension about the current Windows lineups.
I suppose that Chrome Driver does NOT expect Chrome Browser installed in C:\Program Files (x86)\Google\Chrome\Application\chrome.exe on my Windows 7 PC. So I had to override the Chrome binary location explicity as my workaround code shows.