Well! I have purchased a new Dell laptop with windows 8 already installed. They have already made drive c not rest of the drives. Now! how can I create my own desired partitions? I didn't get any windows 8 DVD with it.
As long as you can shrink the partition in disk management ypu wont have a problem creating another partition with the unallocated space created from the shrink.
If your unable to you might try a linux boot cd to do it.
Yes we need to see the Disk Mgmt picture to advise you best. Do NOT allow it to convert to Dynamic which happens if you try to create more than four primary partitions. One will need to be converted to Logical first to add extra partitions!