1. Close all browser windows
2. Go to start menu
3. Type cmd into the search box and press enter
4. In the black window, type ipconfig /flushdns
5. Press enter. Check the resultant message.
6. Your DNS should now be cleared for your PC at Operating System level.
7. Try accessing the website.
8. If you still have a problems:
9. Close Internet Explorer
10. Open Internet Explorer
11. Go to the Tools menu, select Delete Browsing History, check all boxes (except passwords, if desired) and click Delete.
12. Your DNS is now cleared at Browser level.
13. Try the website again.
14. If you still have problems contact your IT department and ask them to flush the DNS at the router level. They will know the best way to do this for your system set up.