Q: about reformat disk where Linux and Window coexist

[Dabin Wang]

I have installed Linux after window 98 installed via partition of disk. 
Now Linux can not start. I want to remove the Linux and reformat the 
free space for windows (i.e., recover to original window environment)

What I did already:
1. In DOS, with FDISK I can not delete the parttition that Linux hold.
2. With Partition Magic, any disk space that Linux uses can not be free 
(i.e. I can not delete any thing).

My question is:
1. How can I free the space that Linux is using? or
2. How can I reformat the whole disk drive and reinstal Windows XP?.


Thanks

Dave