Try checking your Network Management settings. Start -> Settings -> Connections -> Connections. Advanced Tab -> Select Network. The first box should say My ISP. The second should say My Work Network. I know that a lot of people say that they should both be My Work Network but this particular setup that I have described has ALWAYS worked for me. I have tried changing it so that both say My Work Network but then I lose internet.
Otherwise, you could do a hard reset.

In my opinion it's a good thing to do every once in a while anyway.