partitioning - How to I get to my linux partition?

So I got a new hard drive. First, I downloaded Ubuntu on to it, because I didn't have windows 7 yet. So a few days later I bought windows 7, and partitioned it on to the hard drive.

Now, when I start the computer, it goes straight to windows 7. That's fine and all, but how do I get to the Ubuntu partition that's somewhere on the hard drive still? I believe it is an extended partition, not a primary.