Removing dual boot

I have installed Windows XP Home edition on a seperate drive (D: 40gig)as a dual boot with my Win 98SE on drive (c: 42 gig) and XP is the default load.

It installed easy with no problems. I converted the D: drive to NTFS. I now have everything working well in XP and no longer need the Dual Boot.

How do I make it a single boot into XP so I can remove Win 98 and convert that drive to NTFS too. I do not want to lose my settings as it is going well. I am happy to move hardware around to makeD: into C: if necessary.