Question : How can I shrink my C Drive in Vista when I get the "Logical Disk Manager - Access is denied" error message?

I am trying to shrink my C Drive and I get the following error message even though there is plenty of "shrink" space available and I am an "administrator" user.

   "Logical Disk Manager - Access is denied."

I currently have a dual boot with Vista Business 64-bit on my C Drive and XP Pro 64-bit on my D Drive.  My plan was to shrink the C Drive in half and create another Primary Partition to install Windows Server 2008 (primarily to run Virtual Server 2005 R2).

It has taken me a full two days of work, but I have been able to shrink the C Drive from 256Gb to 176Gb leaving 80GB free space.  There is over 26,000Mb of "shrink" left, but when I try to "shrink" another 16GB (so I have 160Gb for C and 96Gb for Windows 2008) I get the "Logical Disk Manager - Access is denied." error message.

%%%    Here are some details about the HDD configuration:

2 x 500GB HDD with a RAID1 (Mirroring)

Primary Partition
   C Drive, 256GB, Vista Business, 64-bit
   (about 40GB used, as indicated above, I have shrunk it to 176GB with 80Gb of free space after it)
Extended Partition
   D Drive, 128GB, XP Pro, 64-bit
   I Drive, 64GB (InfoTech - location for drivers, downloads, IT Stuff)
   S Drive, 16GB (SwapFile - I have a dedicated drive for my Page File)

(This machine has 8 GB RAM and a 6 x 500GB RAID5 Array for the data)

%%% End of Details

Why have I started getting the error message and is there a way to prevent it?

(I have searched the Internet and found several people with the same problem, but no recommended solutions.  I have tried using "Administrator" with same results.  I have Partition Magic 8.2, but it is not compatible with Vista; there is a trial version of Paragon Hard Disk Manager Suite 2008 at http://www.download.com/Paragon-Hard-Disk-Manager-Suite/3000-2248_4-10101053.html - but my preference is to fix Vista first and only use a 3rd party solution as a last resort).

Thank You

Answer : How can I shrink my C Drive in Vista when I get the "Logical Disk Manager - Access is denied" error message?

try bootit -ng, free for what you want :  www.terabyteunlimited.com/       
do NOT install it on the disk - hit cancel
select your partition, and try to resize - what happens ?