How to reset or flush your DNS resolver cache

Windows

1. Hold down the Windows key and press "R" to bring up the Run dialog box.
2. Type ipconfig /flushdns then press "Enter" (be sure there is a space before the forward slash)

Mac OSX

1. Open the Terminal. Navigate to Applications -> Utilities -> Terminal.
2. Flush DNS - Type the following command and hit enter.
   1. Mac OS X Yosemite and later: sudo killall -HUP mDNSResponder
   2. Mac OS X Yosemite v10.10 through v10.10.3.: sudo discoveryutil mdnsflushcache