If system partition is running out of disk space on SBS 2003, you can rely on partition software for Server to increase the size of system partition.
When receiving low disk space warning message on Windows SBS 2003 C drive, you don't need to worry because you can extend the C drive without losing any data or reinstalling system.
If Windows SBS runs out of disk space on disk partition, you can use partition software to extend the partition. With partition softwaer, you can extend a system partition, C drive or data volume on Windows SBS 2003, SBS 2008, and other Windows Servers.
For Windows Server all versions ==> Download IM-Magic Partition Resizer Server