How to change mixed mode to native mode?

Start -> Programs -> Administrative tools -> Active directory users and computers ->
Right click on Domain -> Drag down to properties -> on General tab click on Change
mode button -> Click Yes
Note: By default windows 2003 will be loaded in mixed mode. You can change windows 2003 from mixed mode to native mode, but once if you change mixed mode to native mode you cannot change from native mode to mixed mode.
Note: When you are formatting the disk, if you set the block size as default, windows 2000/XP/2003 divides the partition into 4 KB blocks. When you are creating a file or folder it allocates space to that file or folder in multiples of 4 KB. When you create a new file first time it allocates 4 KB, after 4 KB is filled up it allocates another 4 KB size, it goes on like this until the disk space is completed.