I can't register two DLLs

When trying to register the DLL libfdk-aac-2.dll and hb.dll in the sysWOW64 folder I get this error:

module c:\windows\syswow64\libfdk-aac-2.dll was loaded but the dllregisterserver entry point was not found

Make sure "c:\Windows\sysWOW64\libfdk-aac-2.dll" is a valid DLL or OCX file and try again.

The same with this other DLL hb.dll.
module c:\windows\syswow64\hb.dll was loaded but the dllregisterserver entry point was not found

Make sure "c:\Windows\sysWOW64\hb.dll" is a valid DLL or OCX file and try again.

Since the libfdk-aac-2.dll DLL has both x86 and x64 versions, the x86 version was successfully registered in system 32 but the 64 version was not.

I have tried all these alternatives without success.

Some questions, why do you need to manually register these files, where did you get these files, what is the command you are using to register them, are you sure you have permission to register the files and finally are you sure they are actually .dll & .ocx files?
The more detail you can give the more chance someone might have an answer.

Probably .NET and need to be registered in the GAC with gacutil.

DigitalGoat said:

Some questions, why do you need to manually register these files, where did you get these files, what is the command you are using to register them, are you sure you have permission to register the files and finally are you sure they are actually .dll & .ocx files?
The more detail you can give the more chance someone might have an answer.

Click to expand...

c:\>regsvr32 "c:\Windows\system32\libfdk-aac-2.dll"

Success in registering this.

c:\>regsvr32 "c:\Windows\syswow64\libfdk-aac-2.dll"

c:\>regsvr32 "c:\Windows\syswow64\hb.dll"

Unsuccessful in registering these.

I am the only administrator of the machine I have the permissions.

I got them from these sources and am registering them manually as they don't have installers.

And yes they are really DLLs but I can't register in the sysWOW64 folder only in System32

Codecs.com

libfdk-aac for Windows binary builder

The error would suggest that the files are either not built correctly, as in missing the table required by the .dll register service or are not meant to be registered but rather held in an application's folder structure where they will be found with the application's path settings.
There is this utility from Nirsoft that show the relevant structure of a .dll file : DLL Export Viewer - view exported functions list in Windows DLL

Checking Stack Exchange and other programming related sites the most common causes of the error are; corrupt file, incorrectly built file, file is not meant to be registered.
You will need to determine which applies in this case and whether there is anything you can do to remedy the situation without sourcing the problem files from another location.
If you compiled the files yourself then check your build process to make sure you have included all dependencies necessary for the target architecture.

For the SysWOW64 .dlls, use the 32-bit regsvr32 that is in that foder. So...

c:\> c:\Windows\syswow64\regsvr32 "c:\Windows\syswow64\libfdk-aac-2.dll"


Or opening the Command Prompt from that folder...

C:\Windows\SysWOW64> regsvr32 "c:\Windows\syswow64\libfdk-aac-2.dll"

rick99 said:

For the SysWOW64 .dlls, use the 32-bit regsvr32 that is in that foder. So...

c:\> c:\Windows\syswow64\regsvr32 "c:\Windows\syswow64\libfdk-aac-2.dll"


Or opening the Command Prompt from that folder...

C:\Windows\SysWOW64> regsvr32 "c:\Windows\syswow64\libfdk-aac-2.dll"

Click to expand...

I tried both suggested ways and the problem persists, same error message.

DigitalGoat said:

The error would suggest that the files are either not built correctly, as in missing the table required by the .dll register service or are not meant to be registered but rather held in an application's folder structure where they will be found with the application's path settings.

Click to expand...

When you look on OSDN, the AAC_install.txt reads:

Install AAC libraries
Windows:
1. Download libfdk-aac-2.dll from this folder
2. Go to the installation directory of butt by typing %LOCALAPPDATA%/butt into the file explorer
3. Copy libfdk-aac-2.dll into the installation directory of butt
4. Restart butt

Click to expand...

garlin said:

When you look on OSDN, the AAC_install.txt reads:

Click to expand...

I read the file and this still doesn't explain why I can't register the DLLs in the sysWOW64 folder?

Ro Wood said:

I read the file and this still doesn't explain why I can't register the DLLs in the sysWOW64 folder?

Click to expand...

In order to be registered, a .dll needs an entry point.(header file .h in C/C++)
It is optional as far as code therefore not all .dll can be registered.
You want to register a .dll when its use is system wide, otherwise the app will look
in the folder defined by the installation process/ or system paths.

This resulted in what was called .dll hell at one point as many versions ended up overwriting each other.

In this case, the .dll will be found as it resides in %windir%/subfolders which is pathed.
cmd.exe type set (enter), look for Path.