I have a Windows 2003 Server (Standard) with a 12gb primary C: OS partition that is running out of disk space within 5 minutes of booting up. The primary partition has 450mb of free disk space and the page file is on the secondary D: drive. As soon as the server boots up I can watch the C drive lose disk space from within My Computer every 5 seconds. It goes down to 25mb and then restarts to 450mb and then goes back down again until eventually the server crashes. I've ran Sophos Rootkit Detection, which didn't finish, but showed nothing up to the point of the system crash.