Hi Heaud,

Welcome to WinDrivers!

First off, go here forProduct Specs for your Pavilion 522n. It looks like it came with WinXP. It also should have come with a Recovery Disk. Concerning the onboard sound, it looks like it uses the AC97 Audio.

Go here for drivers for your Pavilion. Nothing specific for audio drivers...it should be on your Recovery Disk. You might also want to read up on HP Desktops - Fixing Sound Problems. Lots of good info there on setup in BIOS, etc.

Concerning your BIOS, yeah, it looks like there are two versions. They are dated only one month apart...you might need both of them.
To check the current BIOS version on the computer, follow the steps below:
Click Start, then Shut Down.
Select Restart, and then click OK.
When the blue Hewlett-Packard screen appears, press F1 to enter the BIOS Setup.
The BIOS revision is listed on the Main menu. Make note of the current BIOS version; you will need this information to determine if a newer revision is available.
To exit the BIOS setup, press F10, select Yes, and then press Enter.
Last but not least, Performing a Full System Recovery in Microsoft Windows XP.

Hope this all helps you out...Good Luck!