Partition Wizard is one of the utilites I looked at, but my first choice would be to use the bootable CD to create the partition and full format it:
http://partitionwizard.com/partition-wizard-bootable-cd.html
I assume you have already used Acronis or Norton Ghost for create an image backup of both the 100MB and Windows partition to an external USB drive.
Also assumes that Partition Wizard's bootable CD can do a "Full" format (after creating one large partition) and that you can restore your image backup to that now reformatted C: partition. More on this later.
Might as well see if running Partition Wizard from within Windows can fix the problem, let me know.
And please don't jump into the Image Backup method (if Partition Wizard doesn't work) before coming up with a documented plan.
JS
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