Might be a bit off-topic but it's the first time I see this problem at someonelse othe than me:
but fdisk seems to be missing from my XP install
I have the same problem with my XP Pro install. On an WIn 98 floppy boot disk I have fdisk but it reports a wrong size of my HD (120GB). It says it's only around 50 GB. I searched the MS site and found out that fdisk won't work with HDs bigger than 64GB but there's a patched version of fdisk that can do that. I downloaded it yet it says it has to be run in MS-DOS mode. Ok, I boot in MS-DOS mode, try to run it again and..."incorrect version of MS-DOS".

So, if I want to run fdisk and get the desired effects, what on Earth should I do? Of course, there are tools like Partition Magic but what if I want to do it in MS-DOS?