I know that it has been a while, but if your are still having issues, try this. It has worked for me on several occasions.
browse to C:\Program files (x86)\google\update
open the install directory
open each directory within it until you find the win bundle that is stated in the popup
delete the file, then the directory within install that contained the win bundle file
browse back up to the update directory and delete the update.exe file located there.
and there you have it the popup is gone.
^.^ Linc