Error 1904.Module C:\Windows\SysWOW64\rapi.dll failed to register. HRESULT -2147220473. Contact your support personnel.

I am getting the above error while installing WMDC 6.1 in Windows 7 professinal 64-bit system. I have sucessfully installed the above on 32-bit windows 7 professional system. but error on 64-bit windows 7 home premium.


Question Info

Last updated March 5, 2020 Views 12,489 Applies to:

Hi vmkolla,


Method 1:

Register the File Manually

To register a specific file again in the registry, while you are working in Microsoft Windows, follow these steps:

  1. Click Start and then type cmd in the start search bar.
  2. Right click on the result and select Run as Administrator.
  3. In the Open window, type the following command, and then hit Enter.

RegSvr32 <filename>

Where <filename> is the name of the file specified in Error 1904


You should receive a message that the file is now correctly registered. If you receive a message that the file is not registered, try the other workarounds.


Method 2:

Clean-Start the Computer

This might be happening if any of the background programs is confliction with the installation process. You may try to install the program in a clean boot state and check if the installation process goes well. You can start Windows 7 by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.


The steps to be performed in clean boot are given below:

1. Log on to the computer by using an account that has administrator rights

2. Click Start, type msconfig.exe in the Start Search box, and then press ENTER to start the System Configuration Utility.

If you are prompted for an administrator password or for confirmation, type your password, or click Continue

3. On the General tab, click Selective Startup, and then click to clear the Load startup items check box. (The Use Original Boot.ini check box is unavailable.)

4. On the Services tab, click to select the Hide all Microsoft services check box, and then click Disable all


Note: Following this step lets Microsoft services continue to run. These services include Networking, Plug and Play, Event Logging, Error Reporting, and other services. If you disable these services, you may permanently delete all restore points. Do not do this if you want to use the System Restore utility together with existing restore points


Once you boot to the desktop try installing the software and check if the issue persists.


For further information on clean boot please follow the below given link:

How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7


After you finish installing the software, follow these steps to reset the computer to start as usual:

1. Click start, type msconfig.exe in the Start Search box, and then press ENTER.

If you are prompted for an administrator password or for confirmation, type your password, or click Continue.

2. On the General tab, click the Normal Startup option, and then click OK.

3. When you are prompted to restart the computer, click Restart



Hope this information is helpful.

Amrita M

Microsoft Answers Support Engineer
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