I have two Win XP installed by mistake on two different partitions namely C:and D:. Now, I want to format both these partitions and INSTALL freshly WinXP on C: only. I used a win98 boot from floppy and got A: prompt. I typed " Format C:". It says unsupported format in C:. How should I format. Please give step-by-step Instruction. Thanks!use the XP install CD and get it to format the partition it is going onto.
Assuming you have a valid Windows XP CD...

For step by step INSTRUCTIONS, please visit the following page at Microsoft and scroll down until you see "How to partition and format your hard disk by using the Windows XP Setup program":

http://support.microsoft.com/kb/313348

Pay special ATTENTION to Step 7:

7. All the existing partitions and the unpartitioned spaces are listed for each physical hard disk. Use the ARROW keys to select the partition or the unpartitioned space where you want to create a new partition. Press D to delete an existing partition, or press C to create a new partition by using unpartitioned space. If you press D to delete an existing partition, you must then press L (or press ENTER, and then press L if it is the System partition) to confirm that you want to delete the partition. REPEAT this step for each of the existing partitions that you want to use for the new partition. When all the partitions are deleted, select the remaining unpartitioned space, and then press C to create the new partition.