Hello sam2505.
Estending a partition until the next one is deleted will destroy every data saved on the second partition; if you want to do that, perform a full backup of the data stored in the partition that you're going to delete.
Furthermore, HP usually create 4 partitions on the hard disk of its PCs; one of these partitions is the Recovery partition (that you can use to perform a full restore of your system) and deleting this partition will make you unable to restore (or install again)
the operating system if you do not have a set of recovery discs.
Bye.
Luigi Bruno