my online works well have had 3 modems in 2 weeks it will not find DNS, I am not knowing what to do

Hello joniander,
 
Welcome to the Webroot Community,
 
Sorry to hear you are having this issue. I was wondering if your Internet Service Provider can help you with this? Otherwise please have a look here at the Microsoft Community.
and look here http://www.wikihow.com/Fix-DNS-Server-Not-Responding-Problem
 
Can you try this below?
Flush your DNS.

• To open the Command Prompt, press ? Win + R and type cmd .
• Type ipconfig /flushdns . Wait for the command to process and then restart your computer.

Hopefully this helps?
 
Happy New Year Joan!:D