Parition Magic 8....help to remove and get back memory to C:

Problem: Running low on memory on c: hard drive. Can't even
defragment. Only 4.5 MB free with 15MB free space within five partitioned drives that I no longer need. I do not want to go through a re install to fix this problem.
 
System: xp(60mb hardrive)  with 100mb of  250 mb exterenal hard drive available.
 
Goal: Remove partitioned hard drive space created by Partition Magic and return that memory to C: drive.  I no longer have a need for Partition Magic.
 
Attempted solution: Used Partition Magic to delete five paritioned hard drives. This was successful but about 15 MB that I expected to go back to the C: drive remains with Partition Magic, listed as "Extended" unused MB.