Your DVD/CD drive should accept the small disc. Open the try and look carefully for a small circular indination for the small disc.
IF yours does not have such, you can always use a friend, neighbor, clasmmate's etc drive who does support the small disc and have them copy it to a thumb/flash drive and/or a memory card or, copy it and send it to you in Email......
The install program should be quite small
BTW Aptiva is OFFICE DEPOT's Brand name, I checked their website for downloads, but bo luck, You could call them and ask if they have a support site for their Aptiva products.