Heres what I did to resize my NTFS Partition from 35 GB to 25 GB :
> Boot with Knoppix CD(version I had 5.0.1)
Select Expert Mode, by typing expert in Boot Prompt
boot: expert
This will take 5 mins to detect your system configuration and take you to Graphical Mode
> Now open a terminal.
> su root (It will switch over to root prompt with out asking for password).
> Type qtparted &
This will open a Graphical box which lists the current partion in your system
> Select the Partition, right click and select resize
Enter your New size ( here I entered 25 GB from my current 35 GB).
Say OK and on Menu Bar Click Save.
> Type init 6, to reboot after saving the configuration
Remove the Disk
The windows system runs consistency checks and you are done !!!
Now Login to Windows and See if the changes have reflected !!!