Hi armageddan and welcome to the forums
According to the HP website, your sound/audio solution is of the AC'97 type. You can obtain generic drivers for this from the hardware manufacturers - in this case it will probably be Realtek (link given below). To verify that this is the case, you will need to look in 'Device Manager'. Click the start orb and type 'Device Manager' into the search box and press enter/return. Click to expand the category 'Sound, video and game controllers' as shown below (this is from my system). If it shows as being a Realtek device then follow the link below, otherwise reply with this information so that we can locate a suitable driver for you.