I needed to be able to dual boot my laptop as the VPN client we use “Aventail” is only available for Windows and I would need to be able to log on from home when I am doing out of hours support. The Kubuntu Dapper install caters for this and offers to resize your Windows partition for you.
However when I tried that it failed saying it was unable to resize. I got a similar result when I tried a manual resize using the qtparted partition manager tool.
The reason was when that I had been using the laptop booted in Windows and surprise, surprise it had had some problems shutting down so I had to do a forced power off. This however left the NTFS partition in a non-clean state. As soon as I booted back into Windows and did a full shutdown then the installer resized the Windoww partition no problem. The moral of the story: First clean your Windows.