How to allow Chrome to access the network in firewall/antivirus?

So not too long ago I decided to download GimpShop (photo editor), and of course it downloaded a load of other crap with it, so every time I opened Google Chrome a pop up in a new tab would come up. But now, suddenly it won't let me access the internet at all (even though my internet connection is totally fine), and I'm not sure why. I've tried everything, uninstalling all the dodgy installations that came with GimpShop (and GimpShop itself) but no change.. I've tried to access my Firewall but it won't even let me remove it from the list and add it again... I can't resolve this problem myself! I want to be rid of all these pop ups and access Google Chrome.