There are two different audio cards shipped with Pavilion DV1000 series Notebooks.
If your Notebooks belong to DV1600 series, your Notebook should have been shipped with Conexant High Definition Audio card.
This can be one of the reason why you are unable to install the Conexant AC Link audio drivers in your Notebooks.
You need to install Microsoft UAA Drivers first before installing the Conexant High Definition Audio Drivers in the Notebook.
Download the Microsoft Universal Audio Architecture(UAA) Drivers for your Notebook from the HP link below :
Please save the file in the Notebook and double click it after the download completes to install the drivers. Restart the Computer once the installation of the Microsoft UAA Drivers is completed.
Now download the Conexant High Definition audio drivers from the link below :
Save the file and double click on it once it is saved to install the Drivers.
This should solve the issue with audio in your Notebooks.
Hope this helps...