Q: Problem with Wifi on all Apple Devices on my Network OS X Yosemite and IOS 8.1.2

Hello Everyone, A few days ago I started to experience WIFI issues on my Home Network with only APPLE DEVICES We have One MacBook Pro 2012, two IPhone 6+s and also a windows PC all running WIFI on a Netgear R7000 Nighthawk (Comcast ISP). The windows PC is working perfectly fine full internet access no issues at at... The IPhones and Mac are the problem... They will not connect to the app store and safari keeps displaying websites not loading images correctly, this also happens in the app store when I can get it to connect and in apps like Istagram and facebook on the Iphones. some images keep showing up with only question marks where images are supposed to be on the iphones and Macbook... Furthermore other times Safari displays the message "safari cannot connect to server" I have tried resetting the router to default settings, Tried resetting the network settings on the IPhones as well, I I have also tried a different router and nothing has worked. Let me also add that I have tried hard resets on the Modem and router.