How do I format an ext3 partition into fat32 or ntfs?
 

I have 3 nos. ext3 partitions and one FAT32 partition. Now, I need to convert one of those ext3 partition into NTFS. How do I do that using mkfs?

Use windoze to make a NTFS file system or fat32 or use a program like Partition Magic.

I doubt that you will be able to convert a partition like that. Unless you find a magic conversion tool, of which I've not heard of in Partition Magic, I see you deleting the file system and reformatting as NTFS.

I was not trying to imply you can convert ext3 to NTFS. To get there you would need to backup the data to another medium, delete the partition, and format the space with a program like Partition Magic or a windoze system.

I hope that is clearer.

You can reformat any partition into NTFS using gparted, which is part of the Gnome desktop. It is included on live cds of Puppy Linux or DSL. The partition to be reformatted must be unmounted and any data on that partition will be lost.
I tried to run mkfs --help in the terminal, but that command was not recognized.