Follow these steps if:

--When you open your file explorer and google drive file stream is NOT appearing in your side bar

--There is a red X or red "?" on the G: Google Drive 

--When you attempt to click the Google Drive and it displays an error saying it is "not installed or inaccessible"

1. Click the start menu in the bottom left corner

2. Type "google"

3. When "Google Drive" appears, click it. This will start up the program again

4. Open up your file explorer again, and now "Google Drive" should be there