Sometimes, administrative systems will require a user to flush their DNS. Without needing to know what that means, here are the steps in case you are asked to do this.
Search in the bottom left corner of your computer for cmd and then click on Command Prompt.
At the command line prompt, you should see something that gives you a flashing cursor at the C:\ drive. If you see another drive, like your U:\ drive, you want to type c: and hit enter so it looks like this:
Now type cd\ and hit enter, then cd \users and hit enter, then cd yourusername and hit enter.
Now that you're in the right directory, you can flush the dns by typing ipconfig /flushdns and hitting enter. That's it! You can type exit to leave the command prompt window.