Hi,
I would do the following:
1) Edit the boot.ini so that there is only the XP installation present and test this boots you straight into XP ok without you need to do anything
2) Within XP you can then use the Disk Management tool to delete the C partition. It would be better though if you used something like Partion Magic as you can then delete the C partition and then expand the XP install into this space
Remember - when you are removing partitions and modifying them you have to assume the worst so ensure you have a full back of your data on an external source.
Thanks.
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