Do you have Packard Bell iMedia XS series 4242 desktop?? Your specs don't mention XS series, but I can't find a 4242 in the regular iMedia series.
If so, I wonder if you have the right driver
Looking at Packard Bell UK website: Support Download
and then navigating to XS iMedia 4242, I come to the link in the pic below.
Note that you cannot choose Windows 7 32 bit at that link. Only 64 bit.
Note that it also says "this page shows only drivers
that are not contained in Windows 7".
Note that XP and Vista have a red X which I assume means no drivers available. I certainly don't see any.
I take the above to mean that Packard Bell has no 32 bit drivers for audio on Windows 7 for this PC.
Can you post the link at Realtek where you found the drivers that you recently downloaded??