SystemRescueCD - free download from Distrowatch includes both partimage which you can use to make a backup image of your win 7 system partition prior to resizing the partitions and QParted which will do the partion resize bits. I have had no problem enlarging XP system partitions in the past, don't see why there should be any issues with Win 7. The Win 7 image made with partimage can be restored onto a larger partition without problems - it only saves bits actually used and not unused space.