Hi Kartor,
Here is a link to the main support page for your laptop:
Compaq Presario F730US Notebook PC*
This link is to the spare parts page for the
F700 series:
HP PartSurfer
As you can see, there are 2 versions of your model. Here are the direct links for those (be sure to select the correct one):
G967UAR HP PartSurfer G967UA HP PartSurfer
If you scroll down the list, you will come to the category
Drive [Drives] and the optical drive is the 2nd listed, part number
453048-001. Please note that I haven't had any cause to order anything directly from them, so you will have to check for more information on ordering by clicking the link
Buy Parts and following the instructions.
Hope this helps.