Launching Chrome once again after closing the browser.

I came across this problem that I cannot find a solution, can someone help.

Script1 (data driven loop) - Logon user1, then go through a bunch of scripts and end with Aliases.browser.BrowserWindow.Close();

Script 2 - Logon user 2 then go through a bunch of scripts and end with Aliases.browser.BrowserWindow.Close();

Script3 - Logon user 3 then go through a bunch of scripts and end with Aliases.browser.BrowserWindow.Close();

NEXT, loops back to Script 1.

I check the task manager, I don't see another instance of Chrome, so I don't understand this error.

error: There is (are) 1 running instance(s) of "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe". New instances will not be launched. 

Has anyone seen this problem?  Is there a way to check if chrome process is running, if so, to clear the chrome.exe before running the next script.