Vista Home Premium sucks, but having preinstalled, and having used it for a couple of weeks before I discovered this I was stuck with a 95GB partition for System and 56GB for Data on my Asus G2S. I looked around a bit and found that you can resize the partition from Disk Management (or DiskPart.exe for you CL fans).  Cool, I was set, ran it with 36GB freespace, and found that I could resize it by 463MB... Surely enough for Damn Small Linux but not quite enough for Vista Ultimate 64-bit. Had to be a fragmentation issue so I ran defrag and got 2GB. Then I deleted or moved around 20GB of various MSDN media and got 6GB. So I went off in search of a better defrag engine... Trying AusLogics Disk Defrag I got another 5GB for a total of 11GB. I ran AusLogics 4 times in a row and it kept reporting 0.33% fragmentation but I wasn't getting any more space... So I went to the old Raxco PerfectDisk , which happens to have been my personal favorite since they used to have a Turbo option (and they do again too). I did a free space consolidation including a reboot and defrag of system files after having moved the paging file onto another drive. When it rebooted finally after just over 1 hour I ran the shrink again and got 46GB. Good enough! I'm installing VU64 now, after which I will install Windows 2008 server on the remaining Data partition.

You Rock Raxco!