I think you are using XP as OS. In this case you can do it easily with a program called Partition Management programs.

Try one of those programs.

http://www.download.com/Norton-PartitionMagic/3000-2248_4-93479.html?tag...

http://www.download.com/Easeus-Partition-Manager/3000-2248_4-10863346.html

if you need further instructions you can PM me.