Re-allocating space in dual-boot machine

[RikuoAmero]

Hey a problem here.

I've got a dual-boot computer, Windows Vista and Windows XP.

In Vista, there are three hard drives (one physical drive in the actual machine). C: Drive is the Vista boot drive, D: is the Data drive, used for storage, and X: is where Windows XP is installed.

When booted in Windows XP, the XP boot drive is D:, Vista is on System C:, (unused when in XP) and Data is J:.

The problem is that the Windows XP partition has only about 20 or so Gigabytes allocated to it, which is now almost full. I have some programs that actually need to be installed on the system drive (in this case, D:) but there's no space. How can I safely take space from the Data drive, and re-allocate it to the XP drive?

Additional Details

Edit: The Data drive J: has about 180 some odd gigabytes, so I want to take space from there and allocate it to the XP system drive D:

[s0teric]

How can I safely take space from the Data drive, and re-allocate it to the XP drive?

I've had trouble with the windows default disk manager so I use paragon partition manager works like a charm

try this - http://thepiratebay.org/torrent/5471043/PARAGON_HARD_DISK_MANAGER_2010_PRO_SUITE_x86

-run the hard disk manager just right click on a partition and hit move/resize partition

-this should make an unallocated partition which you can merge with your xp partition (if I remember correctly)

-you can merge partitions under wizards, advanced, merge partitions

[† L4ugh]

An open source option you could try is Parted Magic. I would make sure you back up your data before you modify your partitions, just in case the process fails.