This is how to resize Win 2003 partition:
First, we need to leave some unallocated space on the right of the extended partition. We can finish this task by right click My PC, and then click Management, Disk Management.
Next, you should enter the cmd interface.
Input Diskpart and you will go to the DISKPART > Interface.
Next, select disk, Select disk O.
At last check the needed partition drive letter with list partition.
Select partition number (1 for example), select it and check whether there is a * behind this partition. If it is confirmed, input extend and you will get the tips that extension succeed.
But this method can cause partition error easily. If you are unfamiliar with cmd, you'd better not try this. You are under a risk of data loss or disaster. Is there any way to resize partition more easily? Yes, you should try to use a third party partition management software.
MiniTool Partition Wizard Server Edition is a professional server partition manager with powerful functions in partition management, it can resize, copy, delete partition and much more. In addition, it can support different file systems and operating systems. Thus, it is the best choice for partition management. Free download the software from the following link:
http://www.partitionwizard.com/download.html.