Even after removing the extension causing the popups and webpage loading the listing of the extension can still be listed in Chrome, and the Policy.
I ended up finding a installer (I don't know how many variants there are) and installing it on my system to end up with the below also that need removing or the gpt.ini modified back.
I have added variables instead of the actual characters to to changing from install to install, I suggest users getting help for it.
gpt.ini has added line of
C:\Windows\System32\GroupPolicy\Machine\Registry.pol) has inside
PReg [ S o f t w a r e \ P o l i c i e s \ G o o g l e \ C h r o m e \ E x t e n s i o n I n s t a l l F o r c e l i s t ......[Characters for extension]....
Edited by Quads, 13 February 2014 - 09:45 PM.