Windows 7 - Volume and Mute Slider Buttons do not work DV 9823cl

I did a clean install of Windows 7 on my Hp DV9823CL. The quickplay and dvd buttons work,but the volume and mute buttons do not. This is what I sent HP:

problem description : I did a clean install of Windows 7. Prior to the clean install all quickplay buttons worked fine. Now the quickplay and the dvd buttons work,but the volume and mute buttons do not work.
troubleshooting : I reinstalled quickplay, as well as the quick play buton drivers that are listed. I also did a troubleshoot that worked once when I removed the battery and put it back in. This also does not fix the problem.

This is what their repsonse was:

Thank you for contacting HP Total Care.
Scott, as I was checking your notebook’s specification I found that your notebook was shipped with Windows Vista. Your notebook is not upgradable to windows 7 as there is no driver available your notebook’s driver page. Your notebook is design to perform its best in Windows Vista. So I request you to get back to the original operating system.
If you need further assistance, please reply to this message and we will be happy to assist you further.
For information on keeping your HP and Compaq products up and running, please visit our Web site

So do they really think, I should dump a better OS and go back to Vista,just because the volume and mute buttons do not work..there must be a solution.