I purchased a new router board, when I tried connecting to it through winbox I get this message ( Router OS missing .dll file). How do I connect to this board? any ideas

Searching for 'missing dll file' in the forums shows that you should try to re-install RouterOS via Netinstall as this is due to a corrupt install.

How do I telnet or get inside the box to even reinstall the OS.

Read the wiki FAQ.

http://wiki.mikrotik.com/wiki/Most_basic_questions