# Are there any guides for modifying/unlocking Realtek drivers yourself, instead of trusting randomly downloaded drivers?



## G502 (Nov 2, 2018)

This forum has several posts with links to unlocked/modified Realtek drivers which enable DTS Interactive and Dolby Digital Live. This is fantastic, and I'm grateful that people have spent time making these available to the community.

However as any IT professional will know, installing system-level drivers from an unknown origin is perhaps the most dangerous thing you can do to your computer. It would be infinitely preferable to take official/signed Realtek drivers and modify them yourself, so that you know you have a driver without any undesirable content.

With that in mind, are there are existing guides or tutorials on how to modify the Realtek drivers to unlock DTSI/DDL without relying on pre-made patchers/executables or drivers (e.g. via a hex editor)?

If not, would anyone be willing to write a small guide or share information about how this is done?

Cheers


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## G502 (Nov 4, 2018)

Alright, since nobody replied I spent some hours performing some basic research myself. Here's what I found:

I compared several of the modified Realtek DLL files posted in the other thread to their official unmodified counterparts using the binary diff tool VBinDiff.exe. I found that only a few bytes of each file had been changed, so whatever changes were made were probably very minimal and simple (i.e. changing a binary flag; DTS off -> DTS on, for example). Under these conditions it's extremely unlikely, if not impossible, that the specific DLLs I tested, at least, could contain anything malicious.

If you want to examine the modifications more deeply, you could probably use something like IDA disassembler or Visual Studio to debug and compare the files.


I ran the patch provided by user Pihto on this forum (realtek.hd.sound.driver-patch.exe) in a disposable virtual machine, and also inside a process-monitored sandbox to explore exactly what the patch was doing. It's a variant of the dup patcher tool which is a legitimate tool used by developers which lets end-users apply patches/fixes to software. In this case, it makes the changes mentioned above to the Realtek DLL files. The patch also runs a registry file containing the following:

```
REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Audio]
"DisableProtectedAudioDG"=dword:00000001
```

It made no other changes to the system and did not appear at all malicious.


I made several attempts at using various pre-downloaded and self-created modified DLL files to enable DDL/DTSI on my motherboard's Realtek chip (a Realtek ALC1150 on an Asus X99-A/USB 3.1 motherboard). Initially these did not work, until I discovered this comment from a user with the same motherboard advising that patching Realtek 2.80 (6.0.1.8004) drivers had worked for them. After using Pihto's patcher on this release of drivers, I finally managed to make DDL and DTSI work (see notes below).


One problem I did notice was that the registry key "DisableProtectedAudioDG" was constantly being deleted, for some reason. This resulted in an error message, "Failed to play test tone" when I attempted to test DDL/DTSI in Windows sound settings. I suspect this was being done either by the Realtek setup program or Windows' own audiodg.exe service. In any case, I made sure that the registry entry was still present *after* installing the modified Realtek setup, and immediately before/after restarting the computer.
*My basic guide to enabling Dolby Digital Live and/or DTS Interactive:*

In a nutshell, the process to follow is this:

Uninstall your existing Realtek drivers and reboot.
Download and extract zip file containing original Realtek HD audio drivers (I used version R2.80 / 6.0.1.8004 downloaded from Softpedia).
Use Pihto's patcher to patch the DLL files. The target filenames are listed on the patcher window. They begin with "Rltk" and may be in "win32" and "win64" subfolders of the Realtek package. You will have to manually select each file to patch and run the patcher multiple times to patch all matching files.
Now run the Realtek setup program. You may be asked to install unsigned drivers. Choose yes.
Do not immediately reboot. Instead, open regedit and ensure the "DisableProtectedAudioDG" registry fix mentioned above is still present. If not, add it again.
Reboot, and DDL/DTSI should be available.
For security reasons you should verify that the Pihto's patch program you're using is the same as the one I tested and found to be (apparently) secure:


```
Filename: realtek.hd.sound.driver-patch.exe
MD5 hash: 0564C191689B27625A5BF817E2FE44F8
SHA256 hash: BEDABC3014C3250008858866047B328C4391F4BF85488080102ECB70543C33FC
```

If you get a message "Failed to play test tone" when testing the new sound options, it likely means that the Windows Audio Device Graph protection is still enabled. Double-check the registry entry above.

If you only hear two sounds (left/right) while playing the test tone, don't worry; apparently this is normal, and 5.1 content will still play normally in real applications.

My original motivation for doing this was so that I could use an optical cable to connect my PC to my Logitech Z906 speakers and play Dolby/DTS content via Media Player Classic HC while still retaining "normal" features like being able to hear Windows system sounds while watching, and control the volume of content via MPC-HC directly instead of having to use my speaker volume. And of course, being able to use 5.1 surround sound with the optical cable which I understand is not possible without DDL/DTSI.


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## erpguy53 (Nov 4, 2018)

another thing to consider, especially for Windows 10 users, is to hide/block any Realtek audio driver updates using wushowhide.diagcab after installing the modded/unsigned drivers - otherwise Win10 may silently install & overwrite the modded Realtek HDA DDL/DTSi drivers with Microsoft WHQL certified ones without any user intervention as it *can* happen to some people (it kinda happened to me once when using an old HP computer with a Realtek ALC888S audio chipset & running Win10 and the DDL/DTSi options were lost after Win10 quietly overwritten the modded driver with an unmodded WHQL variety)


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## Deleted member 178884 (Nov 4, 2018)

I can't even install modded drivers on my x299 gaming carbon - it just throws out an error


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## alanfox2000 (Nov 4, 2018)

erpguy53 said:


> another thing to consider, especially for Windows 10 users, is to hide/block any Realtek audio driver updates using wushowhide.diagcab after installing the modded/unsigned drivers - otherwise Win10 may silently install & overwrite the modded Realtek HDA DDL/DTSi drivers with Microsoft WHQL certified ones without any user intervention as it *can* happen to some people (it kinda happened to me once when using an old HP computer with a Realtek ALC888S audio chipset & running Win10 and the DDL/DTSi options were lost after Win10 quietly overwritten the modded driver with an unmodded WHQL variety)



I think Realtek had fix DTSi problem even the new Realtek UWP app have DTS Connect logo.


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## Osirus (Nov 5, 2018)

G502 said:


> Alright, since nobody replied I spent some hours performing some basic research myself. Here's what I found:



Thank you. This is exactly what I was looking for. The other thread has information spread out too much and a lot of the methods described are outdated.


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## ReconNyko (Nov 19, 2018)

This may help you.
9 Best Reverse Engineering Tools for 2018
Link

If you know how to use the tool
Please post a simple manual.



G502 said:


> This forum has several posts with links to unlocked/modified Realtek drivers which enable DTS Interactive and Dolby Digital Live. This is fantastic, and I'm grateful that people have spent time making these available to the community.
> 
> However as any IT professional will know, installing system-level drivers from an unknown origin is perhaps the most dangerous thing you can do to your computer. It would be infinitely preferable to take official/signed Realtek drivers and modify them yourself, so that you know you have a driver without any undesirable content.
> 
> ...




Non-patch files in the RltkAPO64.dll file
There is no difference in the size of the patch file.
But
The file has been modified






I am an amateur user.
But this tool will help.

The .dll file editor is here
Link


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## Jimmy9303 (Dec 2, 2018)

ReconNyko said:


> This may help you.
> 9 Best Reverse Engineering Tools for 2018
> Link
> 
> ...



It's easy to modding the real first way, when you not know is this:

" 1.Go Open up device manager
2. Go under sound,video, and game controllers
3. Find Realtek High Definition Audio
4. Right click and hit update driver
5. Browse my computer for driver software
6. Let me pick from a list of available drivers on my computer
7. Click Have Disk and hit browse
8. Click on the Realtek HD Audio mod folder and look for win64
9. Click on the HDXRT4 and click ok,
10. Click Next and Yes
After it is done, restart the PC.
You should be good then and also make sure before doing these steps that you have driver enforcement disabled."


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