Ghacks shows you how to partition and un-partition your Hard Drive in Windows

Hard drive partitioning is useful for creating virtual drives and creating disk volumes that can be used for storing particular file types. For example, if you did not want to keep all of your media and documents on Drive (C:), you can create a hard drive partition that will be a new volume separate from (C:). Many users are already familiar with hard drive partitioning, but un-partitioning a hard drive is another issue that some may not be familiar with. In other words, if you have partitions and you want to remove them and merge them back into Drive (C:), how do you do that? This tutorial will take you through the steps of hard drive partitioning and then explain how to un-partition in the event that you need to gain space back on Drive (C:). This pertains only to Windows 7 and Vista, as other versions of Windows do not have a built-in utility for partitioning and require third party software for the task.

  How to Partition and Un-Partition your Hard Drive in Windows