I have a Core 2 Quad Q9550, 8GB of memory, and two 320GB 7200rpm drives in Raid 0. Operating system is Vista Ultimate x64. I turned system restore off and began a defragment, it's over 20 hours now and is still at 94% done. It's been at 94% for more than ten hours. I used the built in Vista defragmenter three days ago.