A. Windows 7 gives you some great options for getting in and out of folders quickly. You've already mentioned the shortcut to Windows Explorer in your Taskbar. But there are some other neat additions as well.
I'll go over those in a bit. First, let's answer your question. It's not terribly difficult to change which directory first shows up in Windows Explorer. In your Taskbar, you'll find the icon for Windows Explorer. It looks like a set of file folders.
Right-click on that icon. You'll see the Jump List open above it. Look near the bottom of this list for Windows Explorer and right-click it. You should see a context menu open next to it. Click on Properties.
In the window that opens up, look for a text field labeled Target. This tells Windows Explorer where to go when it first opens. This is what we'll need to change.