|Hello Derek & riider|
First of all thank you to you both for your assistance; I'll reply to your posts together.
In Device Manager, there are no anomalies whatsoever; no exclamation marks or anything. However, it is as if the on-bard sound card is not detected by the OS (as if it wasn't installed).
The message I get when installing directly driver SP57162 (via InstallShield, as downloaded from the HP website) is (translated freely from French) "The detected material is not taken on board by this IDT package. The installation will be aborted".
As additional information: the only device showing under "Sound Controllers" is "Intel(R) Sound Device for Screens", plus a generic "High Definition Audio Controller" under the "System Devices" category.
Thank you for any suggestion you may have.
Thank you to all volunteers who are so kind to help - N