Sound quality crackle

This is an old Advent laptop. There's no driver on the manufactures website. It's got Realtek sound card as far as I know.
I've already tried the latest driver from Realtek without any success.

Please see below some details of the hardware:

HDAUDIO\FUNC_01&VEN_10EC&DEV_0662&SUBSYS_10190000&REV_1001 HDAUDIO\FUNC_01&VEN_10EC&DEV_0662&SUBSYS_10190000

Compatible:
HDAUDIO\FUNC_01&CTLR_VEN_1039&CTLR_DEV_7502&VEN_10EC&DEV_0662&REV_1001 HDAUDIO\FUNC_01&CTLR_VEN_1039&VEN_10EC&DEV_0662&REV_1001
HDAUDIO\FUNC_01&VEN_10EC&DEV_0662&REV_1001 HDAUDIO\FUNC_01&CTLR_VEN_1039&CTLR_DEV_7502&VEN_10EC&DEV_0662 HDAUDIO\FUNC_01&CTLR_VEN_1039&VEN_10EC&DEV_0662
HDAUDIO\FUNC_01&VEN_10EC&DEV_0662
HDAUDIO\FUNC_01&CTLR_VEN_1039&CTLR_DEV_7502&VEN_10EC
HDAUDIO\FUNC_01&CTLR_VEN_1039&VEN_10EC
HDAUDIO\FUNC_01&VEN_10EC
HDAUDIO\FUNC_01&CTLR_VEN_1039&CTLR_DEV_7502
HDAUDIO\FUNC_01&CTLR_VEN_1039
HDAUDIO\FUNC_01&GF&VEN_10EC&DEV_0662&SUBSYS_10190000&REV_1001
HDAUDIO\FUNC_01

driver key: {4d36e96c-e325-11ce-bfc1-08002be10318}\0000

Please any help?

I was working on a friends Advent 9115. As readers will know it comes with Vista HP. I planned on putting putting 7 on it but got the audio crackles. I tried 8.1 which detected all drivers but still crackles.

At this point i've just reloaded Vista and installed the drivers. Perhaps I could have got the drivers to work for 7/8 but I can't be bothered to try now.

My friend has the driver CD which I have uploaded. Also I found out that there is an identical notebook but with a different branding.

Drivers
Your laptop should have been supplied with a Utility CD which contains a copy of the user manual and all the drivers.
The 9115 is basically a rebadged Uniwill U50SI1 (you should see this printed on the underside of the laptop). I'm fairly certain this is the same as the Gericom Phantom A4 Superlight 53120, the Gericom website contains drivers and a user manual.

UKT Support - Advent 9115 Laptop

This isn't a bump for the OP--it's for Googlers.

Download Image: link coming soon. gone to bed.
Drivers Only: link coming soon. gone to bed.

Just wanted to say a big thanks to Paft.
After spending hours trying to solve this problem (yes, in 2020!) it was his tip that got me down the right path.

I tried countless Realtek driver versions, tried disabling various hardware, all the settings I could think of.

Installing the VISTA drivers in win 7 was what finally worked for me, they can be found in a Uniwill U50SI1 driver package. The drivers have to be extracted from the exe which will not run under Windows 7. The audio works flawlessly for me now though. The driver version is 6.0.1.5464 dated 10/08/2007.

Hope someone else finds this useful.