Why do not you try the way of post # 17?
The Realteka driver on the referenced page is also in the x64 version.
The HDXMATP # .inf file (WIN64 driver directory) contains exactly the same information as in the 8142 / A07 and 8248 / A08 drivers on the Dell website (HDXMATP3.inf files).
REALTEK 8186
;
; INF file for installing Realtek High Definition Audio Driver
;
[Version]
CatalogFile=HDXRT.CAT
Signature = "$chicago$"
Class=MEDIA
ClassGuid={4d36e96c-e325-11ce-bfc1-08002be10318}
Provider=%OrganizationName%
DriverPackageType=PlugAndPlay
DriverPackageDisplayName=%PackageDisplayName%
DriverVer=06/14/2017, 6.0.1.8186
.
.
.
[Manufacturer]
%MfgName% = AzaliaManufacturerID, NTamd64.6.0
[AzaliaManufacturerID.NTamd64.6.0]
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AD
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AE
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C0
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C1
DELL 8142
;
; INF file for installing Realtek High Definition Audio Driver
;
[Version]
CatalogFile=HDXRT.CAT
Signature = "$chicago$"
Class=MEDIA
ClassGuid={4d36e96c-e325-11ce-bfc1-08002be10318}
Provider=%OrganizationName%
DriverPackageType=PlugAndPlay
DriverPackageDisplayName=%PackageDisplayName%
DriverVer=05/02/2017, 6.0.1.8142
.
.
.
[Manufacturer]
%MfgName% = AzaliaManufacturerID, NTamd64.6.0
[AzaliaManufacturerID.NTamd64.6.0]
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AD
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AE
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C0
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C1
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C2
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C3
DELL 8248
;
; INF file for installing Realtek High Definition Audio Driver
;
[Version]
CatalogFile=HDXRT.CAT
Signature = "$chicago$"
Class=MEDIA
ClassGuid={4d36e96c-e325-11ce-bfc1-08002be10318}
Provider=%OrganizationName%
DriverPackageType=PlugAndPlay
DriverPackageDisplayName=%PackageDisplayName%
DriverVer=09/05/2017, 6.0.1.8248
.
.
.
[Manufacturer]
%MfgName% = AzaliaManufacturerID, NTamd64.6.0
[AzaliaManufacturerID.NTamd64.6.0]
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AD
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806AE
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C0
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C1
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C2
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C3
"Realtek Audio" = IntcAzAudModel1028052E, HDAUDIO\FUNC_01&VEN_10EC&DEV_0255&SUBSYS_102806C4
After installing 8186, check if the driver is working.
After installing the driver and restarting the system, I entered the Control Panel / Sounds and checked which devices are set for the input / output.
When you click the Sounds icon, a message may show that certain options that your card does not support must be turned off. Accept this.