Vista H.E Premium- problem with accessing sound?

I would appreciate any help on my inability to get sound on mic. or speakers.
Have tried M.S 'fixit' to no avail.

Vista Home Premium Edition, 32 bit on Compac Pressario Laptop.

Think this problem may have occurred after a MS windows update.

Cannot get any sound from speakers or headphones.
Can only hear hum, crackle from both speakers when plug lead into front of laptop.

I have speaker volume in on position at high setting and can see the levels moving when playing a music file.
The sound button is not muted in Windows Media player.

I have gone into Devices and have a yellow check against the item
Portable Devices
Microsoft WPD FileSystem Volume Device.

When properties viewed it reads 'This device cannot start, (Code 10),check for solutions
Did that, but nothing came back.

The drivers here show as being up to date.
C;\Windows\system32\DRIVERS\UMDF\wpdFs.dll
and
C;\Windows\system32\DRIVERS\WUDFRd.sys

I've tried looking for new drivers, says all up to date; tried disabling, log off, log on, re-enabling this folder (and have tried that also
with the folders in the Sound and Video group.)

The following Sound and video and Game controllers are all showing to be working o.k
with all drivers being up to date.

Conextant High Definition Smart Audio 221
NVIDIA High Definition Audio
Screen Camera
WsAudio_DeviceS(1)
WsAudio_DeviceS(2)
WsAudio_DeviceS(3)
WsAudio_DeviceS(4)
WsAudio_DeviceS(5)
WsAudioDevice_383

W.S Audio Device (4) is the only one showing a moving sound level in the playback panel

In the recording panel, all the devices lines are shown to be working, only no (4)
is showing a moving signal wave. All midi devices are showing 'currently unavailable.'

It would be great to get my system back to normal...

Thank you
Barb