Multimedia Audio Controller Driver

Going by the HP model number in your specs (d4790y), and according to here,

Software & Driver Downloads HP Pavilion d4790y CTO Desktop PC - HP Customer Care (United States - English)

It has either the Realtek (onboard audio) or came with a X-Fi Xtreme Audio (actual card). If it is the onboard Realtek then this should work,

Latest Realtek HD Audio Driver Version

If it came with the X-Fi in it, it depends on whether it is a HP specific OEM card (will only work with the driver from HP), or a "normal" x-Fi which will work with the latest Creative driver.

Open Device Manager, double click on the "multimedia device" to open its properties, then click on the Details tab and scroll to the Hardware IDs and post back what it shows shows the hardware IDs.

Motherboard: ASUSTek Computer INC. Basswood2 (Socket 775)

Also I believe my card is X-Fi Xtreme Audio, I briefly remember looking at it before I installed Windows 7.

Found them (Hardware IDs)

PCI\VEN_1102&DEV_0005&SUBSYS_00331102&REV_00
PCI\VEN_1102&DEV_0005&SUBSYS_00331102
PCI\VEN_1102&DEV_0005&CC_040100
PCI\VEN_1102&DEV_0005&CC_0401

According to here,

PCI Vendor and Device Lists

that is the Xtreme Music, not the Xtreme Audio I thought it was (the Music is a much better card). Now with all that said I would avoid the driver from HP as it is somewhat on the old side (from 2007). That said the latest driver for it from Creative should work with it,

Creative Worldwide Support > X-Fi XtremeMusic

Personally a better option would be to use this,

SB X-Fi PCI Install Disc 1.0 (unofficial) - Creative Labs

it is based on the last beta for the above official driver, with the added benefit of having all necessary apps included with it (Console Launcher, Volume Panel, Alchemy, etc); just do a custom install and select the bits you want, and if you find something you didn't install is needed just run it again and select it.

I just tried the first download you told me, and this is the warning I got:

The Windows operating system running on this computer is not supported by this product.

For the official you need the second one (dated June 16, 2010) as the first is for Vista and XP only.

My bad, I'm an idiot

Thank you very much! It is totally up and running.

You're welcome.