You should be able to unallocate partition 3 and 4 and expend partition 2 to take up the unallocated space.
haven't actually tried this myself before, but Gparted should be able to do it.
You will have to make a bootable USB or burn the ISO to a CD and boot it up.
I'll recommend download Ultimate Boot CD. It has this tool included along with many other cool tools.
It's a good bootable package to have on standby.
Ultimate Boot CD - Download the UBCD