What you should do to get the space up to 7 is first go on the start orb from windows 7 and right-click on computer and select manage. Then click disk management. Wait for it then look for where it shows C. Now select delete. After that right-click your windows 7 partition and click extend partition and go through it. Now the space from the xp bit is added to windows 7 section.
If you need any more help just ask.