My sister has a c and d drive.

C drive is almost full. I would like to unpartician the hard drive to make one big c drive.
Help

To merge partitions:

For XP, you would need a program such as Norton Partition Magic
http://www.symantec.com/norton/partitionmagic

For Vista and XP, Paragon Partition Manager can do this for both Operating Systems
Paragon Partition Manager - hard disk partitioning software.