[computerwizkid]

When you partition a drive with "Disk Management", located in "Computer Management", in Vista and Windows 7, the data doesn't actually move. The program tries to find the most usable space in the original partition (or hard drive if you haven't partitioned your drive already) before space runs out or an "unmovable" file comes up. By unmovable, I mean files such as the page file and the MFT. So, you could possibly have over 300 GB of space available but have only 5 GB available space to partition.
Here is a simple way to fix this. First, you have to download, and install JKDefrag. The next step is to run Windows in Safe Mode, and launch a shortcut of JKDefrag with the following shortcut line, "jkdefrag.exe -a 5 'drive letter':" (without the quotes). That command will move all the data on the partition or volume to the beginning of the drive. This will cause some fragmentation for the time being. After doing that, open up "Computer Management" and select "Disk Management". You should then be able to shrink or be able to create a new partition. Once that process is done, finish up by running "Disk Defragmenter" and run it for all of the volumes on the disk you used to create the partition.

EDIT 12/09/09: Rewrote the guide using proper grammar and easier to understand sentences.

If this still doesn't work, please PM me, and I will try to help you.

This post has been edited by computerwizkid: 08 December 2009 - 07:52 PM