A common problem users run into after formatting their computer is not having internet access.  You had internet access before formatting your computer, and you loaded the operating system successfully back on, so where did the internet go?  This is usually an easy fix.  You are missing the network drivers. 

Here’s what to do – go to another computer that has internet access.  Go to the website of your computer manufacturer, then search the site for your specific computer model.  Make sure to specify your operating system. 

You will want to search for “drivers” for your computer make/model/operating system.  After locating drivers, search specifically for “network drivers”.   Download and save the network driver onto a portable USB drive.  Then, take the USB drive to the recently formatted computer and run and install the driver you just downloaded.  After installing the driver you should be able to access the internet.