resize windows 2003 server system partition

Hi!

I assume your boot drive is located on the RAID - right? In this case, I think it would depend on whether or not the RAID is controlled by a "real" RAID controller (that hides all your drives from the BIOS and oprertating system and presents a single volume spanning all disks instead. These controllers also do the checksum calculation, data distribution, array rebuild and so on on their very own CPU which is soldered onto the controller, so the operating system can simply use the RAID as if it was a plain single hard drive) - or by one of those "I want to be RAID" controllers found on many modern desktop mainboards (these controllers are simply (S)ATA controllers with a somewhat extended BIOS - they are able to recognize a RAID, and their firmware also contains routines for disk I/O to the RAID, so you can boot off those controllers and use them in e.g. DOS. Windows operation needs a special driver for these controllers; without this driver, the system won't recognize a RAID and instead access the single hard drives behind the controller. All work is done on the host CPU - so this can definitiyl impact your system's performance).
If you have a "real" RAID controller that is supported by Linux (to be more precise: by the kernel the GParted LiveCD uses), then it should be possibel to do the job in GParted.
If you have a "wannabe" RAID controller, it is much less probable that GParted will do the job (since Linux has a nice set of RAID functionality that completely runs on your CPU - but is not necessarily compatible with what any RAID controller does - built into the kernel, there's not so much need to support these "wannabe RAID" features).