If you resize a partition that contains data scattered everywhere in the partition, using Windows's built-in disk partitioner, will it actually destroy those data? Or it will gather them together and move to a safe location?
In Vista and W7 the built in partitioner will not move data, so if the partition to be resized is not defragged and consolidated, the amount of allowed shrink will vary.
Partition magic is old software and I would not use it on Vista or Windows 7
Always back up your important data before resizing your partitions, regardless of what software you use.
Paragon has a free software that will do what you need.
You need to use a tool like Partition Magic to re-size your partitions without losing data. The Windows Disk Management tool wasn't originally designed for this purpose.